System, device and method for writing data to protected region

ABSTRACT

A method of writing data to a protected region in response to a request from a host includes receiving a first write request including a first host message authentication code and a first random number from the host, verifying the first write request based on a write count, the first random number, and the first host message authentication code, updating the write count based on a result of verifying the first write request, generating a first device message authentication code based on the updated write count and the first random number, and providing the host with a first response including the first device message authentication code and a result of the verifying of the first write request.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2020-0089165, filed on Jul. 17, 2020, and Korean Patent Application No. 10-2020-0176602, filed on Dec. 16, 2020, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entirety.

BACKGROUND 1. Field

Embodiments relate to a storage device, and more particularly, to a system, device, and method for writing data to a protected region.

2. Description of the Related Art

Storage devices that store data may be used in various applications. Storage devices including memory devices manufactured by semiconductor processes have been widely used.

SUMMARY

Embodiments are directed to a method of writing data to a protected region in response to a request from a host, the method including: receiving a first write request including a first host message authentication code and a first random number from the host; verifying the first write request based on a write count, the first random number, and the first host message authentication code; updating the write count based on a result of verifying the first write request; generating a first device message authentication code based on the updated write count and the first random number; and providing the host with a first response including the first device message authentication code and a result of the verifying of the first write request.

Embodiments are also directed to a storage device configured to communicate with a host, the storage device including: a memory including a protected region; and a controller configured to receive a first write request including a first host message authentication code, a first write count, and a first random number from the host, verify the first write request based on a write count, the first random number, and the first host message authentication code, and write data included in the first write request to the protected region when the verifying of the first write request succeeds.

Embodiments are also directed to a method of writing data to a storage device including a protected region, the method including: generating a first host message authentication code based on a write count and a first random number; providing the storage device with a first write request including the first host message authentication code and the first random number; receiving a first response including a first device message authentication code from the storage device; verifying the first response based on an increment value from the write count, the first random number, and the first device message authentication code; and updating the write count based on a result of the verifying of the first response.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describing in detail example embodiments with reference to the attached drawings in which:

FIG. 1 is a block diagram of a system according to an example embodiment;

FIG. 2 is a diagram of a message data frame according to an example embodiment;

FIGS. 3A and 3B are message diagrams illustrating examples of attacks;

FIG. 4 is a message diagram of a method of writing data to a protected region, according to an example embodiment;

FIG. 5 is a flowchart of a method of writing data to a protected region, according to an example embodiment;

FIG. 6 is a flowchart of a method of writing data to a protected region, according to an example embodiment;

FIG. 7 is a flowchart of a method of writing data to a protected region, according to an example embodiment;

FIG. 8 is a flowchart of a method of writing data to a protected region, according to an example embodiment;

FIG. 9 is a message diagram of a method of writing data to a protected region, according to an example embodiment;

FIGS. 10A and 10B are message diagrams of methods of writing data to a protected region, according to example embodiments;

FIG. 11 is a block diagram of a system 1000 to which a storage device according to an example embodiment is applied;

FIG. 12 is a block diagram of a UFS system 2000 according to an example embodiment;

FIGS. 13A to 13C are diagrams for describing a form factor of a UFS card;

FIG. 14 is a block diagram of a NVM storage 2220 a according to an example embodiment;

FIG. 15 is a block diagram of an NVM storage 2220 b according to an example embodiment;

FIG. 16 is a block diagram of the memory device 2226 of FIG. 15 ;

FIG. 17 is a diagram for describing a 3D V-NAND structure applicable to a UFS device, according to an example embodiment; and

FIG. 18 is a cross-sectional view of a BVNAND structure applicable to a UFS device, according to an example embodiment.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of a system 10 according to an example embodiment. The system 10 may include a storage device 100 and a host 200, which communicate with each other. The system 10 may include, or be included in, a stationary system such as a desktop computer, a workstation, a server, a television, or a video game console; or a portable system such as a laptop computer, a tablet personal computer (PC), a mobile phone, an e-book, or a wearable device. In an example embodiment, the system 10 may be referred to as a storage system.

The host 200 may refer to a device that communicates with the storage device 100, and may also be referred to as a host device. The host 200 may include at least one programmable device such as a central processing unit (CPU), a digital signal processor (DSP), a graphics processing unit (GPU), or a neural-network processing unit (NPU); a reconfigurable device such as a field programmable gate array (FPGA); or a device, such as an intellectual property (IP) core, which provides a fixed function. The host 200 may include a host controller that performs operations described hereinbelow with reference to the drawings. The host controller may include at least one programmable device configured to execute software, at least one reconfigurable device, and/or at least one device that provides a fixed function.

The host 200 may communicate with the storage device 100 based on an interface. For example, the host 200 may communicate with the storage device 100 based on a serial advanced technology attachment (SATA) interface, a small computer small interface (SCSI), a peripheral component interconnect express (PCIe) interface, a universal serial bus (USB), a universal flash storage (UFS) interface, or an embedded multi-media card (eMMC) interface. Referring to FIG. 1 , the host 200 may transmit a request REQ to the storage device 100 and receive a response RES from the storage device 100 based on an interface.

The host 200 may include a random number generator 220, and may provide the storage device 100 with a response RES including a random number generated by the random number generator 220. Thus, the request REQ may include a unique value (e.g., a nonce 24 of FIG. 2 ), and the host 200 may verify a response RES corresponding to the request REQ based on the unique value included in the request REQ. The storage device 100 may extract the unique value from the request REQ, and may verify the request REQ or generate the response RES based on the extracted unique value.

The storage device 100 may be a storage that includes a memory 140 storing data. For example, the storage device 100 may include an embedded device, which supports an embedded UFS (eUFS) or an eMMC, or may be detachably connected to the host 200 like a flash memory card, a compact flash (CF) card, a secure digital (SD) card, a micro-SD card, a mini-SD card, an extreme digital (xD) card, or a memory stick. Referring to FIG. 1 , the storage device 100 may include a controller 120 and the memory 140.

The memory 140 may have a structure for storing data, and may be referred to as a memory device. The memory 140 may include non-volatile memory such as flash memory or resistive random access memory (RRAM). The storage device 100 may include a buffer including volatile memory such as dynamic RAM (DRAM). The storage device 100 may include a buffer-less or DRAM-less storage, which uses a portion of the memory 140 as a buffer. Referring to FIG. 1 , the memory 140 may include a protected region 142. The protected region 142 may be managed by the controller 120, which is described below.

The controller 120 may control the memory 140 and may be referred to as a memory controller. Referring to FIG. 1 , the controller 120 may receive the request REQ from the host 200, control the memory 140 based on the request REQ, and provide the response RES corresponding to the request REQ to the host 200. For example, when the host 200 requests a data write through the request REQ, the controller 120 may write data to the memory 140 based on an address included in the request REQ, and provide the response RES, which indicates completion of the data write, to the host 200. When the host 200 requests a data read through the request REQ, the controller 120 may read data from the memory 140 based on an address included in the request REQ, and provide the response RES including the data to the host 200.

The controller 120 may define the protected region 142 as a portion of the memory 140. The protected region 142 may correspond to a replay protected memory block (RPMB) defined in UFS. The controller 120 may permit only authenticated access to the protected region 142, and thus the host 200 may store data that is intended to be secure, i.e., secure data, in the protected region 142 and may read the secure data from the protected region 142. The storage device 100 and the host 200 may share an authentication key with each other in advance, and authenticate the request REQ and/or the response RES by using the authentication key. For example, referring to FIG. 1 , the controller 120 may use a device key KEY_(D), and the device key KEY_(D) may be stored in a space which is accessible by only the controller 120, e.g., in a portion of the protected region 142. Similarly, the host 200 may use a host key KEY_(H), and the host key KEY_(H) may be stored in a space that is accessible by only the host 200 (or the host controller). Herein, operations performed by the controller 120 may be simply referred to as being performed by the storage device 100.

The device key KEY_(D) and the host key KEY_(H) may be respectively provisioned to the storage device 100 and the host 200. The device key KEY_(D) and the host key KEY_(H) may be respectively provisioned during the manufacture of the storage device 100 and during the manufacture of the host 200. The device key KEY_(D) may be provisioned to the storage device 100 by the request REQ of the host 200. The device key KEY_(D) that has been provisioned may not be rewritten and read. In an example embodiment, the device key KEY_(D) may be identical to the host key KEY_(H).

The controller 120 may include a register 122. The register 122 may include a write count (or a write counter). The controller 120 may count a write operation performed on the protected region 142 in response to a write request to the protected region 142. The host 200 may provide the request REQ (i.e., a write count read request) to read a current write count to the storage device 100, and the controller 120 may read the write count stored in the register 122 and provide the response RES including the write count to the host 200. The host 200 may provide the request REQ to write data, i.e., a write request, to the storage device 100, and the request REQ may include a write count. When the write count included in the request REQ is different from a current write count, i.e., the write count stored in the register 122, the controller 120 may determine a failure of the verification of the request REQ. Herein, a write count that is managed by the host 200 may be referred to as a host write count, and a write count that is managed by the storage device 100, i.e., the controller 120, may be referred to as a device write count.

Even though the storage device 100 and the host 200 authenticate access to the protected region 142 by using the write count, the device key KEY_(D), and the host key KEY_(H), various attacks may be made on the system 10 in an attempt to obtain and/or change data stored in the protected region 142 or to insert an error in access to the protected region 142. For example, as described with reference to FIGS. 3A and 3B below, an attack may be made to insert an error in access of writing data to the protected region 142. This attack may cause a serious error in the system 10. As described below, the host 200 may generate a request REQ to write data based on the random number generated by the random number generator 220. The storage device 100 may verity the request REG based on the random number included in the request REQ, and may provide a response RES corresponding to the request REQ to the host 200. The host 200 may identify whether the operation requested by the request REQ, i.e., a write operation, has been successfully completed, by verifying the response RES based on the random number used to generate the request REQ. Thus, a man-in-the-middle (MITM) attack may be effectively detected by the storage device 100 and the host 200, error insertion by the MITM attack may be prevented, and the security of the protected region 142 may be enhanced. In addition, a change in an interface between the storage device 100 and the host 200 may be unnecessary or minimized, and thus the security of the protected region 142 may be further efficiently and easily enhanced.

FIG. 2 is a diagram of a message data frame 20 according to an example embodiment. In the present example embodiment, the message data frame 20 of FIG. 2 refers to an RPMB message data frame of UFS. The request REQ and the response RES for access to the protected region 142 in FIG. 1 may have the message data frame 20 in common. Referring to FIG. 2 , the message data frame 20 may include a plurality of fields 21 through 29. FIG. 2 will now be described with additional reference to FIG. 1 .

Referring to FIG. 2 , the message data frame 20 may be 512 bytes in length. A stuff bytes field 21, which indicates the start of the message data frame 20 and is 196 bytes in length, may be at the front of the message data frame 20. The message data frame 20 may sequentially include a message authentication code (MAC) field 22, a data field 23, a nonce field 24, a write count field (or a write counter field) 25, an address field 26, a block count field 27, a result field 28, and a message type field 29, following the stuff bytes field 21. As described below, the data field 23, the nonce field 24, the write count field 25, the address field 26, the block count field 27, the result field 28, and the message type field 29 may be used together with an authentication key to generate the message authentication code field 22, and may be collectively referred to as a message MSG. Each of the request REQ and the response RES may be referred to as including a message authentication code MAC and the message MSG. Herein, the nonce field 24 and the write count field 25 from among the fields included in the message MSG will be mainly illustrated and described, and illustrations and descriptions of the other fields of the message MSG may be omitted.

The message authentication code field 22 may be 32 bytes in length and may be included in each of the request REQ and the response RES. The message authentication code field 22 may have a value that is used to verify the message data frame 20, i.e., the request REQ and the response RES. For example, the host 200 may generate the message authentication code MAC (which may be referred to as a host message authentication code) to be included in the request REQ based on the message MSG (which may be referred to as a host message herein) to be included in the request REQ and the host key KEY_(H). The storage device 100 may verify the message authentication code MAC (i.e., the host message authentication code) included in the request REQ based on the message MSG (i.e., the host message) included in the request REQ and the device key KEY_(D). Similarly, the storage device 100 may generate the message authentication code MAC (which may be referred to as a device message authentication code herein) to be included in the response RES based on the message MSG (which may be referred to as a device message herein) to be included in the response RES and the device key KEY_(D). The host 200 may verify the message authentication code MAC (i.e., the device message authentication code) included in the response RES based on the message MSG (i.e., the device message) included in the response RES and the host key KEY_(H). The message authentication code field 22 may be used to transmit an authentication key having a 32-byte length in an authentication key programming request (message type=0001 h).

The message authentication code MAC may be generated from an authentication key and the message MSG based on a hash function, and may be referred to as a hash message authentication code (HMAC). Each of the storage device 100 and the host 200 may generate the message authentication code MAC from an authentication key and concatenation (i.e., bytes [228:511]) of the fields of the message MSG based on a hash function, such as Message-Digest algorithm 5 (MD5), Secure Hash Algorithm 1 (SHA-1), or SHA-256, and may include a hash engine that implements the hash function.

The data field 23 may be 256 bytes in length and may be included in each of the request REQ and the response RES. For example, the data field 23 included in the request REQ may correspond to data that is to be written to the storage device 100, and the data field 23 included in the response RES may correspond to data read from the storage device 100. The nonce field 24 may have a 16-byte length, may be included in each of the request REQ and the response RES, and may include a random number generated by the host 200. The write count field 25 may have a 4-byte length, may be included in each of the request REQ and the response RES, and may include a value that results from counting write operations on the protected region 142. The nonce field 24 and the write count field 25 may be used together with the message authentication code field 22 to verify the message data frame 20.

The address field 26 may have a 2-byte length, may be included in each of the request REQ and the response RES, and may include a value that indicates a portion of the protected region 142 to which the data field 23 is written or from which the data field 23 is read. The block count field 27 may have a 2-byte length, may be included in each of the request REQ and the response RES, and may include the number of 256-byte logical blocks requested to be read or programmed. The result field 28 may have a 2-byte length, may be included in the response RES, and may include a value that indicates a result of an operation.

The message type field 29 may have a 2-byte length and may be included in each of the request REQ and the response RES. The message type field 29 included in the request REQ may be referred to as a request message type and may have a value that defines a request. For example, the request message type may include a value that indicates one of an authenticate key programming request, a write count read request, an authenticated data write request, an authenticated data read request, a result read request, a secure write protection configuration block write request, and a secure write protection configuration block read request. A response message type may include a value that indicates one of an authenticate key programming response, a write count read response, an authenticated data write response, an authenticated data read response, a secure write protection configuration block write response, and a secure write protection configuration block read response.

FIGS. 3A and 3B are message diagrams illustrating examples of MITM attacks. An attacker 32 a may be between a host 31 a and a storage device 33 a, referring to FIG. 3A. An attacker 32 b may be between a host 31 b and a storage device 33 b, referring to FIG. 3B. It is assumed in FIGS. 3A and 3B that requests are write requests with respect to a protected region and that a response is generated in response to a write request without a separate request (e.g., a result read request). Hereinafter, redundant descriptions will be omitted.

Referring to FIG. 3A, the host 31 a may include at least one processor that executes software including an operating system (OS) and applications executed on the OS. The OS may include a device driver that provides an interface with the storage device 33 a to an application. The attacker 32 a may be in the form of software in the device driver, or between the device driver and the storage device 33 a, and may initiate a relay attack as described below.

In operation S30 a, the host 31 a may issue a first write request REQ₁ and the attacker 32 a may receive the first write request REQ₁. As described with reference to FIG. 2 , the first write request REQ₁ may include a plurality of fields, and a message type field from among the plurality of fields may have a value (for example, 0003h) corresponding to a write request. In operation S31 a, the attacker 32 a may store the first write request REQ₁, which was provided by the host 31 a in operation S30 a, and may provide the first write request REQ₁ to the storage device 33 a in operation S36 a, which is described below.

In operation S32 a, the attacker 32 a may provide a second write request REQ₂ to the storage device 33 a. The attacker 32 a may generate the second write request REQ₂, which is different from the first write request REQ₁, to obtain a response indicating a failure of verification of write request, i.e., a first response RES₁ in operation S34 a, and may provide the second write request REQ₂ to the storage device 33 a. For example, the attacker 32 a may generate the second write request REQ₂ by changing at least one field included in the first write request REQ₁, e.g., the message authentication code MAC and/or the data field.

In operation S33 a, the storage device 33 a may determine a failure of verification of the second write request REQ₂. For example, the storage device 33 a may compare a message verification code generated based on the device key KEY_(D) and at least one field included in the second write request REQ₂, with the message authentication code MAC included in the second write request REQ₂, and may identify that the second write request REQ₂ is not an authenticated request due to the discrepancy between the message verification code and the message authentication code MAC.

In operation S34 a, the storage device 33 a may issue a first response RES₁ indicating the failure of the verification of the second write request REQ₂, and the attacker 32 a may receive the first response RES₁. In operation S35 a, the attacker 32 a may store the first response RES₁, which is provided from the storage device 33 a in operation S34 a, and provide the first response RES₁ to the host 31 a in operation S39 a, which is described below.

In operation S36 a, the attacker 32 a may provide the first write request REQ₁ to the storage device 33 a. The attacker 32 a may provide the storage device 33 a with the first write request REQ₁, which been stored in operation S31 a, without changes.

In operation S37 a, the storage device 33 a may determine a success of verification of the first write request REQ₁. Because the first write request REQ₁ provided from the attacker 32 a in operation S36 a is identical to that issued by the host 31 a in operation S30 a, the storage device 33 a may identify the first write request REQ₁ as an authenticated request. Thus, data included in the first write request REQ₁ may be normally written to the storage device 33 a.

In operation S38 a, the storage device 33 a may issue a second response RES₂ indicating the success of the verification of the first write request REQ₁, and the attacker 32 a may receive the second response RES₂ from the storage device 33 a. In operation S39 a, the attacker 32 a may provide the first response RES₁ to the host 31 a. The attacker 32 a may provide the host 31 a with the first response RES₁, which indicates the failure of the verification of the second write request REQ₂ and has been stored in operation S35 a, instead of the second response RES₂ indicating the success of the verification of the first write request REQ₁. Thus, the host 31 a may identify that a write operation requested by the first write request REQ₁ issued in operation S30 a has failed, and the storage device 33 a may normally store the data requested to be written by the first write request REQ₁. Thus, the host 31 a may identify a state that is different from the real state of the storage device 33 a, because of the attacker 32 a, and an error may occur in a system including the host 31 a and the storage device 33 a.

Referring to FIG. 3B, in operation S30 b, the host 31 b may issue the first write request REQ₁ and the attacker 32 b may receive the first write request REQ₁. In operation S31 b, the attacker 32 b may store the first write request REQ₁. The attacker 32 b may store the first write request REQ₁ provided by the host 31 b in operation S30 b, and provide the first write request REQ₁ to the storage device 33 b in operation S33 b, which is described below. Referring to FIG. 3B, the attacker 32 b may not provide any write request to the storage device 33 b after storing the first write request REQ₁.

In operation S32 b, the host 31 b may issue the second write request REQ₂ and the attacker 32 b may receive the second write request REQ₂. For example, the host 31 b may issue the second write request REQ₂, which includes second data that is different from first data included in the first write request REQ₁.

In operation S33 b, the attacker 32 b may provide the first write request REQ₁ to the storage device 33 b. The attacker 32 b may provide the storage device 33 b with the first write request REQ₁, which has been stored in operation S31 b, without changes, instead of the second write request REQ₂ received in operation S32 b to write the second data.

In operation S34 b, the storage device 33 b may determine a success of verification of the first write request REQ₁. Because the first write request REQ₁ provided from the attacker 32 b in operation S33 b is identical to that issued by the host 31 b in operation S30 b, the storage device 33 b may identify the first write request REQ₁ as an authenticated request. Thus, the first data included in the first write request REQ₁ may be normally written to the storage device 33 b.

In operation S35 b, the storage device 33 b may issue the first response RES₁ indicating the success of the verification of the first write request REQ₁, and the attacker 32 b may receive the first response RES₁ from the storage device 33 b. In operation S36 b, the attacker 32 b may provide the first response RES₁ to the host 31 b. Thus, the host 31 b may identify that a write operation of the second data requested by the second write request REQ₂ issued in operation S32 b has succeeded, while the storage device 33 b may store the first data, which is requested to be written by the first write request REQ₁. Thus, the host 31 b may identify a state that is different from the real state of the storage device 33 b, because of the attacker 32 b, and an error may occur in a system including the host 31 b and the storage device 33 b.

FIG. 4 is a message diagram of a method of writing data to a protected region, according to an example embodiment. Compared with FIGS. 3A and 3B, a write request of FIG. 4 may include a random number, which may be referred to as a nonce.

Referring to FIG. 4 , in operation S401, a host 41 may provide a write count read request REQ_(WC) to a storage device 42. For example, a message type field among a plurality of fields included in the write count read request REQ_(WC) may have a value (e.g., 0002 h) corresponding to a write count read request.

In operation S402, the storage device 42 may provide a write count read response RES_(WC) to the host 41. For example, a message type field among a plurality of fields included in the write count read response RES_(WC) may have a value (e.g., 0200 h) corresponding to a write count read response, and a read count may have a device write count K_(D). The host 41 may set a host write count K_(H) to be the device write count K_(D) included in the write count read response RES_(WC).

In operation S403, the host 41 may generate a first nonce N₁. For example, the host 41 may generate the first nonce N₁ corresponding to a random number generated by a random number generator. The first nonce N₁ may be different from a nonce included in a previously issued write request.

In operation S404, the host 41 may generate a first host message authentication code MAC_(H1). For example, referring to FIG. 4 , the host 41 may generate the first host message authentication code MAC_(H1) from first data D₁, the host write count K_(H), the first nonce N₁, and the host key KEY_(H) based on a hash function h. Thus, the first host message authentication code MAC_(H1) may depend on the first nonce N₁ generated in operation S403.

In operation S405, the host 41 may provide a first request REQ₁ to the storage device 42. For example, a message type field among a plurality of fields included in the first request REQ₁ may have a value (e.g., 0003 h) corresponding to an authenticated data write request. Referring to FIG. 4 , the first request REQ₁ may include the first host message authentication code MAC_(H1), the first data D₁, the host write count K_(H), and the first nonce N₁. The first request REQ₁ may be a write request for requesting a write of the first data D₁ to a protected region, and the host write count K_(H) included in the first request REQ₁ may be identical to the device write count K_(D) received from the storage device 42 in operation S402.

In operation S406, the host 41 may save the first nonce N₁. As described below, the storage device 42 may use the first nonce N₁ to generate a response corresponding to the first request REQ₁, i.e., the first response RES₁ of operation S410. The host 41 may save the first nonce N₁ to verify the first response RES₁. The host 41 may store the first nonce N₁ in a secure register.

In operation S407, the storage device 42 may verify the first request REQ₁. For example, the storage device 42 may verify the first request REQ₁ based on the device key KEY_(D) and the first host message authentication code MAC_(H1), the first data D₁, the host write count K_(H), and the first nonce N₁ included in the first request REQ₁. The storage device 42 may verify the first request REQ₁ based on not only the host write count K_(H) but also the first nonce N₁, and thus a MITM attack may be detected, as is described in further detail with reference to FIGS. 10A and 10B. When the verification of the first request REQ₁ has succeeded, the storage device 42 may write the first data D₁ to the protected region. An example of operation S407 is described with reference to FIG. 5 .

In operation S408, the storage device 42 may update the device write count K_(D). The storage device 42 may update the device write count K_(D) based on a result of the verification of the first request REQ₁ in operation S407, and thus the device write count K_(D) may be maintained or changed. An example of operation S408 is described with reference to FIG. 6 .

In operation S409, the storage device 42 may generate a first device message authentication code MAC_(D1). For example, referring to FIG. 4 , the storage device 42 may generate the first device message authentication code MAC_(D1) from the device write count K_(D), the first nonce N₁, and the device key KEY_(D), based on the hash function h. The device write count K_(D), which is used to generate the first device message authentication code MAC_(D1), may have a value updated in operation S408.

In operation S410, the storage device 42 may provide the first response RES₁ to the host 41. For example, a message type field among a plurality of fields included in the first response RES₁ may have a value (e.g., 0300 h) corresponding to an authenticated data write response. Referring to FIG. 4 , the first response RES₁ may include the first device message authentication code MAC_(D1) generated in operation S409. The first response RES₁ may also include a result having a value corresponding to a success or a failure according to the result of the verification of the first request REQ₁ in operation S407.

In operation S411, the host 41 may verify the first response RES₁. For example, the host 41 may verify the first response RES₁ based on the host key KEY_(H), the first nonce N₁, the host write count K_(H), and the first device message authentication code MAC_(D1). The host 41 may use an increment value of the host write count K_(H) during the verification of the first response RES₁. The host 41 may verify the first response RES₁ based on the first nonce N₁ saved in operation S406, and thus a MITM attack may be detected, as described in further detail with reference to FIGS. 10A and 10B. When the verification of the first response RES₁ has succeeded, the host 41 may rely on the result included in the first response RES₁. On the other hand, when the verification of the first response RES₁ has failed, the host 41 may not rely on the result included in the first response RES₁. An example of operation S411 is described with reference to FIG. 7 .

In operation S412, the host 41 may update the host write count K_(H). For example, the host 41 may update the host write count K_(H) based on a result of the verification of the first response RES₁ in operation S411, and thus the host write count K_(H) may be maintained or changed. An example of operation S412 is described with reference to FIG. 8 .

FIG. 5 is a flowchart of a method of writing data to a protected region, according to an example embodiment. In detail, the flowchart of FIG. 5 illustrates operation S407′ as an example of operation S407 of FIG. 4 of the storage device 42 verifying the first request REQ₁. Referring to FIG. 5 , operation S407′ may include a plurality of operations S4071, S407_2, S407_3, S407_4, S407_5, and S407_6. Operation S407′ of FIG. 5 may be performed by the storage device 42 of FIG. 4 . FIG. 5 will now be described with additional reference to FIG. 4 .

Referring to FIG. 5 , in operation S4071, the device write count K_(D) may be compared with the host write count K_(H). For example, the storage device 42 may compare the host write count K_(H) included in the first request REQ₁ received from the host 41 with the device write count K_(D), which is managed by the storage device 42. Referring to FIG. 5 , when the device write count K_(D) is identical to the host write count K_(H), operation S407_2 may be performed subsequently. On the other hand, when the device write count K_(D) is different from the host write count K_(H), a failure of the verification of the first write request REQ₁ may be determined, and operations S407_7 and S407_8 may be performed subsequently.

In operation S407_2, it may be determined whether a nonce list NL includes the first nonce N₁. As described with reference to FIGS. 1 and 4 , the host 41 may generate a random number when generating a write request, and may include a nonce corresponding to the random number, and thus the write request may have a nonce of a unique value. The storage device 42 may collect nonces included in a request when verification of the request fails, and may manage a nonce list NL including the collected nonces. The storage device 42 may store the nonce list NL in a memory device (for example, RAM) included in a controller (for example, the controller 120 of FIG. 1 ) and/or a partial region (for example, the protected region 142 of FIG. 1 ) of a memory. When the nonce list NL includes a nonce identical to the first nonce N₁, the storage device 42 may identify that the first request REQ₁ is invalid. Thus, referring to FIG. 5 , when the first nonce N₁ is not included in the nonce list NL, operation S407_3 may be performed subsequently. On the other hand, when the first nonce N₁ is included in the nonce list NL, a failure of verification of the first write request REQ₁ may be determined, and operations S407_7 and S407_8 may be performed subsequently.

In operation S407_3, a first host message verification code MVC_(H1) may be generated. For example, referring to FIG. 5 , the storage device 42 may generate the first host message verification code MVC_(H1) from the first data D₁, the device write count K_(D), the first nonce N₁, and the device key KEY_(D), based on the hash function h. The storage device 42 may extract the first data D₁ and the first nonce N₁ from the first request REQ₁, and may generate the first host message verification code MVC_(H1) based on not only the extracted first data D₁ and the extracted first nonce N₁, but also the device write count K_(D) and the device key KEY_(D).

In operation S407_4, the first host message verification code MVC_(H1) and the first host message authentication code MAC_(H1) may be compared with each other. When the first data D₁, the host write count K_(H), the first nonce N₁, and the host key KEY_(H) used by the host 41 to generate the first host message authentication code MAC_(H1) in operation S404 of FIG. 4 are identical to the first data D₁, the device write count K_(D), the first nonce N₁, and the device key KEY_(D) used by the storage device 42 to generate the first host message verification code MVC_(H1) in operation S407_3, respectively, the first host message verification code MVC_(H1) may be identical to the first host message authentication code MAC_(H1). Referring to FIG. 5 , when the first host message verification code MVC_(H1) is identical to the first host message authentication code MAC_(H1), a success of verification of the first request REQ₁ may be determined, and operations S407_5 and S407_6 may be performed subsequently. On the other hand, when the first host message verification code MVC_(H1) is different from the first host message authentication code MAC_(H1), a failure of verification of the first request REQ₁ may be determined, and operations S407_7 and S407_8 may be performed subsequently.

When a success of verification of the first request REQ₁ is determined, a result in operation S407_5 may be set to be a value corresponding to the success. As described with reference to FIG. 4 , the result set in operation S407_5 may be included in the first response RES₁, which is provided by the storage device 42 to the host 41 in response to the first request REQ₁ (or a separate result read request). Next, in operation S407_6, the nonce list NL may be updated. For example, when verification of the first request REQ₁ has succeeded as shown in FIG. 5 , the storage device 42 may delete nonces included in the nonce list NL, namely, nonces respectively included in requests of which verifications have failed and been collected.

When a failure of verification of the first request REQ₁ is determined, a result in operation S407_7 may be set to be a value corresponding to the failure. As described with reference to FIG. 4 , the result set in operation S407_7 may be included in the first response RES₁, which is provided by the storage device 42 to the host 41 in response to the first request REQ₁ (or a separate result read request). Next, in operation S407_8, the nonce list NL may be updated. For example, when verification of the first request REQ₁ has failed as shown in FIG. 5 , the first nonce N₁ may be added to the nonce list NL.

FIG. 6 is a flowchart of a method of writing data to a protected region, according to an example embodiment. In detail, the flowchart of FIG. 6 illustrates operation S408′ as an example of operation S408 of FIG. 4 , in which the storage device 42 updates the device write count K_(D) based on a result of the verification of the first request REQ₁. Referring to FIG. 6 , operation S408′ may include operation S408_2 and operation S408_4. In an example embodiment, operation S408′ of FIG. 6 may be performed by the storage device 42 of FIG. 4 . FIG. 6 will now be described with additional reference to FIG. 4 .

Referring to FIG. 6 , in operation S408_2, a value that is set based on the result may be identified. As described with reference to FIG. 5 , when the verification of the first request REQ₁ has succeeded, the storage device 42 may set the result as a value corresponding to a success, and, when the verification of the first request REQ₁ has failed, the storage device 42 may set the result as a value corresponding to a failure. Referring to FIG. 6 , when the verification of the first request REQ₁ has failed, operation S408′ may be concluded, and thus the device write count K_(D) may be maintained.

When the verification of the first request REQ₁ has succeeded, the device write count K_(D) may be increased in operation S408_4. For example, referring to FIG. 6 , the storage device 42 may increase the device write count K_(D) by 1, and may store the device write count K_(D) in a register (for example, the register 122 of FIG. 1 ). Similarly, as described with reference to FIG. 8 , when the verification of the first request REQ₁ succeeds, the host 41 may also increase the host write count K_(H) by 1, and thus subsequent write requests may be processed validly.

FIG. 7 is a flowchart of a method of writing data to a protected region, according to an example embodiment. In detail, the flowchart of FIG. 7 illustrates operation S411′ as an example of operation S411 of FIG. 4 , in which the host 41 verifies the first response RES₁. Referring to FIG. 7 , operation S411′ may include a plurality of operations S411_2, S411_4, S411_6, and S411_8. In an example embodiment, operation S411′ of FIG. 7 may be performed by the host 41 of FIG. 4 . FIG. 7 will now be described with additional reference to FIG. 4 .

Referring to FIG. 7 , in operation S411_2, a first device message verification code MVC_(D1) may be generated. For example, the host 41 may generate the first device message verification code MVC_(D1) from an increased host write count K_(H)+1, the first nonce N₁, and the host key KEY_(H), based on the hash function h. As described with reference to FIGS. 4 and 6 , when a write of the first data D₁ has been normally completed by the first request REQ₁ in the storage device 42, the first device message authentication code MAC_(D1) included in the first response RES₁ may be generated based on the device write count K_(D) increased by 1. Thus, the host 41 may use not only the host key KEY_(H) and the first nonce N₁ saved in operation S406 of FIG. 4 , but also the host write count K_(H) increased by 1, in order to verify the first response RES₁.

In operation S411_4, the first device message verification code MVC_(D1) and the first device message authentication code MAC_(D1) may be compared with each other. When the device write count K_(D), the first nonce N₁, and the device key KEY_(D) used by the storage device 42 to generate the first device message authentication code MAC_(D1) in operation S409 of FIG. 4 are identical to the increased host write count K_(H)+1, the first nonce N₁, and the host key KEY_(H) used by the host 41 to generate the first device message verification code MVC_(D1) in operation S411_2, the first device message verification code MVC_(D1) and the first device message authentication code MAC_(D1) may be identical to each other. Referring to FIG. 7 , when the first device message verification code MVC_(D1) is identical to the first device message authentication code MAC_(D1), a success of the verification of the first response RES₁ may be determined, in operation S411_6. On the other hand, when the first device message verification code MVC_(D)m is different from the first device message authentication code MAC_(D1), a failure of the verification of the first response RES₁ may be determined, in operation S411_8.

FIG. 8 is a flowchart of a method of writing data to a protected region, according to an example embodiment. In detail, the flowchart of FIG. 8 illustrates operation S412′ as an example of operation S412 of FIG. 4 , in which the host 41 updates the host write count K_(H) based on a result of the verification of the first response RES₁. Referring to FIG. 8 , operation S412′ may include operation S412_2 and operation S412_4. In an example embodiment, operation S412′ of FIG. 8 may be performed by the host 41 of FIG. 4 . FIG. 8 will now be described with additional reference to FIG. 4 .

Referring to FIG. 8 , in operation S412_2, a result of the verification of the first response RES₁ may be identified. As described with reference to FIG. 7 , when the first device message verification code MVC_(D1) is identical to the first device message authentication code MAC_(D1), the host 41 may determine a success of the verification of the first response RES₁, and, when the first device message verification code MVC_(D1) is different from the first device message authentication code MAC_(D1), the host 41 may determine a failure of the verification of the first response RES₁. Referring to FIG. 8 , when the verification of the first response RES₁ has failed, operation S412′ may be concluded, and thus the host write count K_(H) may be maintained.

When the verification of the first response RES₁ has succeeded, the host write count K_(H) may be increased in operation S412_4. For example, referring to FIG. 8 , the host 41 may increase the host write count K_(H) by 1, and may generate a subsequent write request based on the increased host write count K_(H).

FIG. 9 is a message diagram of a method of writing data to a protected region, according to an example embodiment. In the illustration of FIG. 9 , compared with the illustration of FIG. 4 , a storage device 92 may provide a response including a nonce to a host 91. In FIG. 9 , it is assumed that the host 91 is an authenticated entity accessible to a protected region of the storage device 92. Redundant descriptions given above with reference to FIG. 4 will be omitted.

Referring to FIG. 9 , the host 91 may provide the write count read request REQ_(WC) to the storage device 92 in operation S901, and the storage device 92 may provide the write count read response RES_(WC) to the host 91 in operation S902. For example, a message type field from among the plurality of fields included in the write count read request REQ_(WC) may have a value (for example, 0002 h) corresponding to a write count read request, and a message type field from among the plurality of fields included in the write count read response RES_(WC) may have a value (for example, 0200 h) corresponding to a write count read response. Referring to FIG. 9 , the write count read response RES_(WC) may include the device write count K_(D).

In operation S903, the host 91 may generate the first nonce N₁. In operation S904, the host 91 may generate the first host message authentication code MAC_(H1). For example, referring to FIG. 9 , the host 91 may generate the first host message authentication code MAC_(H1) based on the first data D₁, the host write count K_(H), the first nonce N₁, and the host key KEY_(H), based on a hash function h.

In operation S905, the host 91 may provide the first request REQ₁ to the storage device 92. For example, a message type field among the plurality of fields included in the first request REQ₁ may have a value (e.g., 0003 h) corresponding to an authenticated data write request. Referring to FIG. 9 , the first request REQ₁ may include the first host message authentication code MAC_(H1), and may include the first data D₁, the host write count K_(H), and the first nonce N₁ used to generate the first host message authentication code MAC_(H1). In operation S906, the host 91 may save the first nonce N₁. The first nonce N₁ saved in operation S906 may be used to verify a response provided by the storage device 92 in response to the first request REQ₁, namely, the first response RES₁ of operation S909.

In operation S907, the storage device 92 may increase the device write count K_(D) by 1. For example, the storage device 92 may verify the first request REQ₁ provided by an authenticated host 91, and may increase the device write count K_(D) by 1 in response to a success of the verification of the first request REQ₁. In operation S908, the storage device 92 may generate the first device message authentication code MAC_(D1). Referring to FIG. 9 , the storage device 92 may generate the first device message authentication code MAC_(D1) based on the device write count K_(D), the first nonce N₁, and the device key KEY_(D), based on a hash function h. In this case, the device write count K_(D) may have a value increased in operation S907.

In operation S909, the storage device 92 may provide a first response RES₁ to the host 91. For example, a message type field among a plurality of fields included in the first response RES₁ may have a value (e.g., 0300 h) corresponding to an authenticated data write response. When compared with the first response RES₁ of FIG. 4 , the first response RES₁ may further include the first nonce N₁. For example, the storage device 92 may generate not only the first device message authentication code MAC_(D1) and a result, but also the first response RES₁ including the first nonce N₁. Thus, the host 91 may verify the first response RES₁ based on not only the first device message authentication code MAC_(D1), but also the first nonce N₁ included in the first response RES₁. Thus, similar to the description given with reference to FIG. 5 , the host 91 may compare the first nonce N₁ stored in operation S906 with the first nonce N₁ included in the first response RES₁ received in operation S909, and, when the two first nonces are different from each other in contrast with the illustration of FIG. 9 , the host 91 may determine a failure of the verification of the first response RES₁, regardless of a result of the verification of the first device message authentication code MAC_(D1).

In operation S910, the host 91 may increase the host write count K_(H) by 1. For example, the host 91 may verify the first response RES₁ provided by the storage device 92, and may increase the host write count K_(H) by 1 in response to a success of the verification of the first response RES₁. Thus, the host write count K_(H) updated in operation S910 may be identical to the device write count K_(D) updated in operation S907. As described with reference to FIG. 7 , the host 91 may verify the first device message authentication code MAC_(D1) based on the increased host write count K_(H)+1, before updating the host write count K_(H).

In operation S911, the host 91 may generate a second nonce N₂. The second nonce N₂ for the second request REQ₂ and the second response RES₂ (described below) may be different from the above-described first nonce N₁ for the first request REQ₁ and the first response RES₁. The second nonce N₂ may not be able to be predicted by the host 91 or an agent outside the host 91. Thus, each write request issued by the host 91 may have a unique value, i.e., a nonce, and one unique value may be used in an authenticated pair of a write request and a write response.

In operation S912, the host 91 may generate a second host message authentication code MAC_(H2). For example, referring to FIG. 9 , the host 91 may generate the second host message authentication code MAC_(H2) based on second data D₂, the host write count K_(H), the second nonce N₂, and the host key KEY_(H), based on a hash function h. In this case, the host write count K_(H) may have a value increased in operation S910.

In operation S913, the host 91 may provide a second request REQ₂ to the storage device 92. For example, a message type field among a plurality of fields included in the second request REQ₂ may have a value (e.g., 0003 h) corresponding to an authenticated data write request. Referring to FIG. 9 , the second request REQ₂ may include the second host message authentication code MAC_(H2), and may include the second data D₂, the host write count K_(H), and the second nonce N₂ used to generate the second host message authentication code MAC_(H2). In operation S914, the host 914 may save the second nonce N₂, and may use the second nonce N₂ to verify a subsequent response, i.e., the second response RES₂.

In operation S914, the storage device 92 may increase the device write count K_(D) by 1. For example, the storage device 92 may verify the second request REQ₂ provided by an authenticated host 91, and may increase the device write count K_(D) by 1 in response to a success of the verification of the second request REQ₂. In operation S916, the storage device 92 may generate a second device message authentication code MAC_(D2). Referring to FIG. 9 , the storage device 92 may generate the second device message authentication code MAC_(D2) based on the device write count K_(D), the first nonce N₂, and the device key KEY_(D), based on a hash function h. In this case, the device write count K_(D) may have a value increased in operation S915.

In operation S917, the storage device 92 may provide a second response RES₂ to the host 91. For example, a message type field among a plurality of fields included in the second response RES₂ may have a value (e.g., 0300 h) corresponding to an authenticated data write response. Similar to the first response RES₁, the second response RES₂ may include the second nonce N₂, and thus the host 91 may verify the second response RES₂ based on not only the second device message authentication code MAC_(D2), but also the second nonce N₂ included in the second response RES₂. Thus, differently from FIG. 9 , when the second nonce N₂ included in the second response RES₂ is different from the second nonce N₂ saved in operation S914 due to an attacker, the host 91 may determine a failure of the verification of the second response RES₂.

In operation S918, the host 91 may increase the host write count K_(H) by 1. For example, the host 91 may verify the second response RES₂ provided by the storage device 92, and may increase the host write count K_(H) by 1 in response to a success of the verification of the second response RES₂. Thus, the host write count K_(H) updated in operation S918 may be identical to the device write count K_(D) updated in operation S915. As described with reference to FIG. 7 , the host 91 may verify the second device message authentication code MAC_(D2) based on the increased host write count K_(H)+1, before updating the host write count K_(H).

FIGS. 10A and 10B are message diagrams of methods of writing data to a protected region, according to example embodiments. In detail, the message diagrams of FIGS. 10A and 10B illustrate operations of detecting MITM attacks described above with reference to FIGS. 3A and 3B. Redundant descriptions given above with the drawings will be omitted.

Referring to FIG. 10A, in operation S101 a, a host 101 b may issue the write count read request REQ_(WC) and an attacker 102 a may receive the write count read request REQ_(WC). For example, a message type field among a plurality of fields included in the write count read request REQ_(WC) may have a value (e.g., 0002 h) corresponding to a write count read request. In operation S102 a, the attacker 102 a may transmit the write count read request REQ_(WC) to a storage device 103 a without changes, and the storage device 103 a may receive the write count read request REQ_(WC).

In operation S103 a, the storage device 103 a may issue the write count read response RES_(WC), and the attacker 102 a may receive the write count read response RES_(WC). For example, a message type field among a plurality of fields included in the write count read response RES_(WC) may have a value (e.g., 0002 h) corresponding to a write count read response. In operation S104 a, the attacker 102 a may transmit the write count read response RES_(WC) to the host 101 a without changes, and the host 101 a may receive the write count read response RES_(WC). Referring to FIG. 10A, the write count read response RES_(WC) may include the device write count K_(D).

In operation S105 a, the host 101 a may generate the first nonce N₁. In operation S106 a, the host 101 a may generate the first host message authentication code MAC_(H1) based on the first data D₁, the host write count K_(H), the first nonce N₁, and the host key KEY_(H), for the first request REQ₁, based on a hash function h. In operation S107 a, to write the first data D₁, the host 101 a may issue the first request REQ₁ including the first host message authentication code MAC_(H1), the first data D₁, the host write count K_(H), and the first nonce N₁. For example, a message type field among the plurality of fields included in the first request REQ₁ may have a value (e.g., 0003 h) corresponding to an authenticated data write request.

In operation S108 a, the attacker 102 a may store the first request REQ₁. As described with reference to FIG. 3A, the attacker 102 a may store the first request REQ₁ received from the authenticated host 101 a in operation S107 a, in order to provide the first request REQ₁ to the storage device 103 a later. Next, in operation S109 a, the attacker 102 a may provide a changed first request REQ₁′ to the storage device 103 a. For example, a message type field among the plurality of fields included in the changed first request REQ₁′ may have a value (e.g., 0003 h) corresponding to an authenticated data write request. To obtain a response indicating a failure of verification of a write request, the attacker 102 a may generate the changed first request REQ₁′ by changing the first request REQ₁. For example, referring to FIG. 10A, the attacker 102 a may generate first data D1′ by changing the first data D₁, and may generate a changed first host message authentication code MAC_(H1)′ based on the changed first data D1′. Thus, referring to FIG. 10A, the changed first request REQ₁′ may include the changed first host message authentication code MAC_(H1)′, the changed first data D1′, the host write count K_(H), and the first nonce N₁.

In operation S110 a, the storage device 103 a may determine a failure of verification of the changed first request REQ₁′. For example, the storage device 103 a may identify the host write count K_(H) identical to the device write count K_(D), but may identify that a host message verification code generated based on the changed first data D1′, the device write count K_(D), the first nonce N₁, and the device key KEY_(D) is different from the changed first host message authentication code MAC_(H1)′. Thus, referring to FIG. 10A, the storage device 103 a may set a result as a value corresponding to a failure.

In operation S111 a, the storage device 103 a may generate the first device message authentication code MAC_(D1). For example, referring to FIG. 10A, the storage device 103 a may generate the first device message authentication code MAC_(D1) based on the device write count K_(D), the first nonce N₁, and the device key KEY_(D), based on a hash function h. Due to a failure of verification of the changed first request REQ₁′, the device write count K_(D) used to generate the first device message authentication code MAC_(D1) may be maintained, and may have a value provided to the host 101 a in operation S103 a.

In operation S112 a, the storage device 103 a may issue the first response RES₁, and the attacker 102 a may receive the first response RES₁. For example, a message type field among a plurality of fields included in the first response RES₁ may have a value (e.g., 0300 h) corresponding to an authenticated data write response. Referring to FIG. 10A, the first response RES₁ may include the first device message authentication code MAC_(D1) and the result. As set in operation S110 a, the result may have a value corresponding to the failure.

In operation S113 a, the attacker 102 a may store the first response RES₁. As described with reference to FIG. 3A, the attacker 102 a may store the first request REQ₁ received from the storage device 103 a in operation S112 a, in order to provide the first response RES₁ to the host 101 a later. Next, in operation S114 a, the attacker 102 a may provide the first request REQ₁ to the storage device 103 a. Thus, the attacker 102 a may obtain the first response RES₁ from the storage device 103 a and then may provide the first request REQ₁ stored in operation S108 a to the storage device 103 a.

In operation S115 a, the storage device 130 a may determine a failure of verification of the first request REQ₁. Although the first request REQ₁ is identical to that issued by the authenticated host 101 a in operation S107 a, the storage device 103 a may identify that the first nonce N₁ included in the first request REQ₁ is identical to the first nonce N₁ used to verify the changed first request REQ₁′ in operation S110 a. Thus, the storage device 103 a may determine a failure of the verification of the first request REQ₁ as described above with reference to FIG. 5 , and may set a result as a value corresponding to the failure as shown in FIG. 10A. Thus, differently from FIG. 3A, writing of the first data D₁ to the storage device 103 a may fail.

In operation S116 a, the storage device 103 a may generate a second device message authentication code MAC_(D2). For example, referring to FIG. 10A, the storage device 103 a may generate the first device message authentication code MAC_(D1) based on the device write count K_(D), the first nonce N₁, and the device key KEY_(D), based on a hash function h. Due to a failure of verification of the first request REQ₁, the device write count K_(D) used to generate the second device message authentication code MAC_(D2) may be maintained, and may have a value provided to the host 101 a in operation S103 a.

In operation S117 a, the storage device 103 a may issue the second response RES₂, and the attacker 102 a may receive the second response RES₂. For example, a message type field among a plurality of fields included in the second response RES₂ may have a value (e.g., 0300 h) corresponding to an authenticated data write response. Referring to FIG. 10A, the second response RES₂ may include the second device message authentication code MAC_(D2) and the result, and, as set in operation S115 a, the result may have a value corresponding to the failure. Thus, the attacker 102 a may identify a failure of writing of the first data D₁, differently from FIG. 3A.

In view of the above, in spite of the failure of writing of the first data D₁, the attacker 102 a may provide the host 101 a with the first response RES₁ received from the storage device 103 a in operation S112 a, as in FIG. 3A. In this case, the host 101 a may generate a host message verification code to verify the first response RES₁, and the host message verification code may be identical to the first device message authentication code MAC_(D1) included in the first response RES₁. Thus, the host 101 a may determine a success of verification of the first response RES₁, and may rely on a write failure indicated by the result included in the first response RES₁. Even when the attacker 102 a provides the host 101 a with the second response RES₂ received from the storage device 103 a in operation S117 a, the host 101 a may determine a success of the verification of the second response RES₂, and may rely on a write failure indicated by the result included in the second response RES₂. Thus, the host 101 a may identify a first state where the first data D₁ has not been written to the storage device 103 a, and the attacker 102 a may fail to make a state different from the first state, namely, a second state where the first data D₁ has been successfully written to the storage device 103 a.

Referring to FIG. 10B, in operation S101 b, a host 101 b may issue the write count read request REQ_(WC) and an attacker 102 b may receive the write count read request REQ_(WC). For example, a message type field among a plurality of fields included in the write count read request REQ_(WC) may have a value (e.g., 0002 h) corresponding to a write count read request. In operation S102 b, the attacker 102 b may transmit the write count read request REQ_(WC) to a storage device 103 b without changes, and the storage device 103 b may receive the write count read request REQ_(WC).

In operation S103 b, the storage device 103 a may issue the write count read response RES_(WC), and the attacker 102 b may receive the write count read response RES_(WC). For example, a message type field among a plurality of fields included in the write count read response RES_(WC) may have a value (e.g., 0002 h) corresponding to a write count read response. In operation S104 b, the attacker 102 b may transmit the write count read response RES_(WC) to the host 101 b without changes, and the host 101 b may receive the write count read response RES_(WC). Referring to FIG. 10B, the write count read response RES_(WC) may include the device write count K_(D).

In operation S105 b, the host 101 b may generate the first nonce N₁. In operation S106 b, the host 101 b may generate the first host message authentication code MAC_(H1) based on the first data D₁, the host write count K_(H), the first nonce N₁, and the host key KEY_(H), for the first request REQ₁, based on a hash function h. In operation S107 b, to write the first data D₁, the host 101 b may issue the first request REQ₁ including the first host message authentication code MAC_(H1), the first data D₁, the host write count K_(H), and the first nonce N₁, and the attacker 102 b may receive the first request REQ₁. For example, a message type field among the plurality of fields included in the first request REQ₁ may have a value (e.g., 0003 h) corresponding to an authenticated data write request.

In operation S108 b, the host 101 b may save the first nonce N₁ in order to verify a response corresponding to the first request REQ₁. In operation S109 b, the attacker 102 b may store the first request REQ₁. As described with reference to FIG. 3B, the attacker 102 b may store the first request REQ₁ received from the authenticated host 101 b in operation S107 b, in order to provide the first request REQ₁ to the storage device 103 b later.

In operation S110 b, the host 101 b may generate the second nonce N₂. The second nonce N₂ for the second request REQ₂ may be different from the first nonce N₁ used to generate the first request REQ₁. In operation S111 b, the host 101 b may generate the second host message authentication code MAC_(H2) based on the second data D₂, the host write count K_(H), the second nonce N₂, and the host key KEY_(H), for the second request REQ₂, based on a hash function h. At this time, a response indicating a success of a write operation has not been received in response to the first request REQ₁, and accordingly the host write count K_(H) may be identical to the host write count K_(H) used to generate the first host message authentication code MAC_(H1) in operation S106 b. In operation S112 b, to write the second data D₂, the host 101 b may issue the second request REQ₂ including the second host message authentication code MAC_(H2), the second data D₂, the host write count K_(H), and the second nonce N₂, and the attacker 102 b may receive the second request REQ₂. For example, a message type field among a plurality of fields included in the second request REQ₂ may have a value (e.g., 0003 h) corresponding to an authenticated data write request. In operation S113 b, the host 101 b may save the second nonce N₂.

In operation S114 b, the attacker 102 b may provide the first request REQ₁ to the storage device 103 b. The attacker 102 b may provide the storage device 103 b with the first request REQ₁ stored in operation S108 b, without changes. Thus, referring to FIG. 10B, the first request REQ₁ including the first host message authentication code MAC_(H1), the first data D₁, the host write count K_(H), and the first nonce N₁ may be provided to the storage device 103 b.

In operation S115 b, the storage device 130 b may determine a success of verification of the first request REQ₁. For example, the storage device 103 b may individually identify the host write count K_(H) identical to the device write count K_(D) and the first nonce N₁ different from a previous nonce No, and may generate a message verification code identical to the first host message authentication code MAC_(H1). Thus, referring to FIG. 10B, the storage device 103 b may set a result as a value corresponding to a success.

In operation S116 b, the storage device 103 b may generate the first device message authentication code MAC_(D1). For example, referring to FIG. 10B, the storage device 103 b may generate the first device message authentication code MAC_(D1) based on the device write count K_(D), the first nonce N₁, and the device key KEY_(D), based on a hash function h. Due to a success of verification of the first request REQ₁, the device write count K_(D) used to generate the first device message authentication code MAC_(D1) may have a value obtained by increasing, by 1, the value provided to the host 101 b in operation S103 b.

In operation S117 b, the storage device 103 b may issue the first response RES₁, and the attacker 102 b may receive the first response RES₁. For example, a message type field among a plurality of fields included in the first response RES₁ may have a value (e.g., 0300 h) corresponding to an authenticated data write response. Referring to FIG. 10B, the first response RES₁ may include the first device message authentication code MAC_(D1) and the result. As set in operation S115 b, the result may have a value corresponding to the success. In operation S118 b, the attacker 102 b may transmit the first response RES₁ to the host 101 b, without changes.

In operation S119 b, the host 101 b may determine a failure of verification of the first response RES₁. The first device message authentication code MAC_(D1) included in the first response RES₁ may be generated based on the first nonce N₁ in operation S116 b, whereas the message verification code generated by the host 101 b in operation S119 b may be based on the second nonce N₂ saved in operation S113 b. Thus, the first device message authentication code MAC_(D1) may be different from the message verification code, and the host 101 b may determine a failure of the verification of the first response RES₁. In an example embodiment, as described above with reference to FIG. 9 , when the first response RES₁ includes the first nonce N₁, the host 101 b may identify that the first nonce N₁ is different from the second nonce N₂, and accordingly may determine a failure of the verification of the first response RES₁. Thus, the host 101 b may not rely on a write success indicated by the result included in the first result RES₁. Thus, the attacker 102 b may fail to allow the host 101 b to identify a state of the storage device 103 b as a second state different from a first state where the second data D2 has not been stored in the storage device 103 b, the second state where the second data D2 has been stored in the storage device 103 b.

FIG. 11 is a block diagram of a system 1000 to which a storage device according to an example embodiment may be applied. The system 1000 of FIG. 11 may be, e.g., a mobile system such as a portable communication terminal (a mobile phone), a smartphone, a tablet PC, a wearable device, a healthcare device, or an Internet of Things (IoT) device. However, the system 1000 of FIG. 11 is not limited to a mobile system and may be a PC, a laptop computer, a server, a media player, or an automotive device such as a navigation device. Hereinafter, a suffix attached to a reference numeral (e.g., ‘a’ in 1200 a and ‘a’ in 1300 a) is for discriminating a plurality of circuits configured to perform the same facility.

Referring to FIG. 11 , the system 1000 may include a main processor 1100, memories 1200 a and 1200 b, and storage devices 1300 a and 1300 b, and may include one or more of an image capturing device 1410, a user input device 1420, a sensor 1430, a communication device 1440, a display 1450, a speaker 1460, a power supplying device 1470, and a connecting interface 1480.

The main processor 1100 may control a general operation of the system 1000, e.g., control operations of the other components included in the system 1000. The main processor 1100 may be implemented by a general-purpose processor, an exclusive processor, an AP, or the like.

The main processor 1100 may include one or more CPU cores 1110 and may include a controller 1120 configured to control the memories 1200 a and 1200 b and/or the storage devices 1300 a and 1300 b. The main processor 1100 may include an accelerator block 1130 that is an exclusive circuit configured to perform HS data calculation such as artificial intelligence (AI) data calculation. The accelerator block 1130 may include a graphics processing unit (GPU), a neural processing unit (NPU), a data processing unit (DPU), and/or the like, and may be implemented by a separate chip physically independent to the other components in the main processor 1100.

The memories 1200 a and 1200 b may be used as a main memory device of the system 1000 and may include a volatile memory such as static random access memory (SRAM) and/or DRAM or include an NVM such as flash memory, PRAM, and/or RRAM. The memories 1200 a and 1200 b may be implemented in the same package as the main processor 1100.

The storage devices 1300 a and 1300 b may function as a nonvolatile storage device storing data regardless of whether power is supplied thereto, and may have a larger storage capacity than the memories 1200 a and 1200 b. The storage devices 1300 a and 1300 b may include storage controllers 1310 a and 1310 b and NVM storages 1320 a and 1320 b storing data under control of the storage controllers 1310 a and 1310 b, respectively. The NVM storages 1320 a and 1320 b may include V-NAND flash memory of a two-dimensional (2D) or three-dimensional (3D) structure, or another type of NVM such as PRAM and/or RRAM.

The storage devices 1300 a and 1300 b may be included in the system 1000 physically separated from the main processor 1100, or may be implemented in the same package as the main processor 1100. The storage devices 1300 a and 1300 b may have a form such as a memory card form to be detachably coupled to the other components in the system 1000 through an interface such as the connecting interface 1480 described below. The storage devices 1300 a and 1300 b may be devices to which a standard protocol such as a UFS protocol is applied, but are not limited thereto.

The image capturing device 1410 may capture a still image or a moving picture, and may include a camera, a camcorder, a webcam, and/or the like.

The user input device 1420 may receive various types of data from a user of the system 1000, and may include a touch pad, a keypad, a keyboard, a mouse, a microphone, and/or the like.

The sensor 1430 may sense various types of physical quantities, which may be obtained from the outside, and convert the sensed physical quantity into an electrical signal. The sensor 1430 may include a temperature sensor, a pressure sensor, an illumination sensor, a position sensor, an acceleration sensor, a biosensor, a gyroscope, and/or the like.

The communication device 1440 may perform signal transmission and reception between the system 1000 and other devices outside the system 1000 according to various communication protocols. The communication device 1440 may be implemented using an antenna, a transceiver, a modem, and/or the like.

The display 1450 and the speaker 1460 may function as output devices configured to output visual information and auditory information to the user of the system 1000, respectively.

The power supplying device 1470 may convert power supplied from a battery (not shown) in the system 1000 and/or an external power source, and supply the converted power to each component in the system 1000.

The connecting interface 1480 may provide a connection between the system 1000 and an external device connected to the system 1000 to transmit and receive data to and from the system 1000. The connecting interface 1480 may be implemented by various interface schemes such as an advanced technology attachment (ATA) interface, a serial ATA (SATA) interface, an external SATA (e-SATA) interface, a small computer small interface (SCSI), a serial attached SCSI (SAS), a peripheral component interconnection (PCI) interface, a PCI express (PCIe) interface, an NVM express (NVMe) interface, an Institute of Electrical and Electronics Engineers (IEEE) 1394 interface, a universal serial bus (USB) interface, a secure digital (SD) card interface, a multi-media card (MMC) interface, an embedded MMC (eMMC) interface, a UFS interface, an embedded UFS (eUFS) interface, and a compact flash (CF) card interface.

FIG. 12 is a block diagram of a UFS system 2000 according to an example embodiment. The UFS system 2000 is a system conforming to a UFS standard issued by the Joint Electron Device Engineering Council (JEDEC) and may include a UFS host 2100, a UFS device 2200, and a UFS interface 2300. The above description of the system 1000 of FIG. 11 may also be applied to the UFS system 2000 of FIG. 12 within a range that does not conflict with a description made below with reference to FIG. 12 .

Referring to FIG. 12 , the UFS host 2100 and the UFS device 2200 may be connected to each other through the UFS interface 2300. When the main processor 1100 of FIG. 11 is an AP, the UFS host 2100 may be implemented as a part of the AP. A UFS host controller 2110 and a host memory 2140 may correspond to the controller 1120 in the main processor 1100 and the memories 1200 a and 1200 b of FIG. 11 , respectively. The UFS device 2200 may correspond to the storage devices 1300 a and 1300 b of FIG. 11 , and a UFS device controller 2210 and an NVM storage 2220 may correspond to the storage controllers 1310 a and 1310 b and the NVM storages 1320 a and 1320 b of FIG. 11 , respectively.

The UFS host 2100 may include the UFS host controller 2110, an application 2120, a UFS driver 2130, the host memory 2140, and a UFS interconnect (UIC) layer 2150. The UFS device 2200 may include the UFS device controller 2210, the NVM storage 2220, a storage interface 2230, a device memory 2240, a UIC layer 2250, and a regulator 2260. The NVM storage 2220 may include a plurality of storage units 2221, and the storage unit 2221 may include a V-NAND flash memory of a 2D or 3D structure or another type of NVM such as PRAM and/or RRAM. The UFS device controller 2210 and the NVM storage 2220 may be connected to each other through the storage interface 2230. The storage interface 2230 may be implemented to conform to a standard protocol such as a toggle or open NAND flash interface (ONFI) protocol.

The application 2120 may indicate a program, which desires to communicate with the UFS device 2200 to use a facility of the UFS device 2200. The application 2120 may transmit an input-output request (IOR) to the UFS driver 2130 for an input to or an output from the UFS device 2200. The IOR may indicate a data read request, a data write request, a data discard request, and/or the like but is not limited thereto.

The UFS driver 2130 may manage the UFS host controller 2110 through a UFS-host controller interface (HCI). The UFS driver 2130 may translate an IOR generated by the application 2120 into a UFS command defined by a UFS standard, and transmit the translated UFS command to the UFS host controller 2110. One IOR may be translated into a plurality of UFS commands. A UFS command may be basically a command defined by a SCSI standard but may be a UFS standard exclusive command.

The UFS host controller 2110 may transmit the UFS command translated by the UFS driver 2130 to the UIC layer 2250 in the UFS device 2200 through the UIC layer 2150 and the UFS interface 2300. In this process, a UFS host register 2111 in the UFS host controller 2110 may act as a command queue (CQ).

The UIC layer 2150 in the UFS host 2100 may include a MIPI M-PHY 2151 and a MIPI UniPro 2152, and the UIC layer 2250 in the UFS device 2200 may also include a MIPI M-PHY 2251 and a MIPI UniPro 2252.

The UFS interface 2300 may include a line through which a reference clock signal REF_CLK is transmitted, a line through which a hardware reset signal RESET_n for the UFS device 2200 is transmitted, a pair of lines through which a differential input signal pair DIN_T and DIN_C is transmitted, and a pair of lines through which a differential output signal pair DOUT_T and DOUT_C is transmitted.

A frequency value of the reference clock signal REF_CLK provided from the UFS host 2100 to the UFS device 2200 may be one of, e.g., four values, e.g., 19.2 MHz, 26 MHz, 38.4 MHz, and 52 MHz, but is not limited thereto. The UFS host 2100 may change the frequency value of the reference clock signal REF_CLK even during an operation, i.e., even while data is being transmitted and received between the UFS host 2100 and the UFS device 2200. The UFS device 2200 may generate clock signals of various frequencies from the reference clock signal REF_CLK received from the UFS host 2100, by using a phase-locked loop (PLL) or the like. In addition, the UFS host 2100 may set a value of a data rate between the UFS host 2100 and the UFS device 2200 based on the frequency value of the reference clock signal REF_CLK. Thus, the value of the data rate may be determined depending on the frequency value of the reference clock signal REF_CLK.

The UFS interface 2300 may support multiple lanes, and each lane may be implemented by a differential pair. For example, the UFS interface 2300 may include one or more reception lanes and one or more transmission lanes. In FIG. 12 , the pair of lines through which the differential input signal pair DIN_T and DIN_C is transmitted may form a reception lane, and the pair of lines through which the differential output signal pair DOUT_T and DOUT_C is transmitted may form a transmission lane. Although FIG. 12 shows one transmission lane and one reception lane, the number of transmission lanes and the number of reception lanes may vary.

The reception lane and the transmission lane may transmit data in a serial communication scheme, and full-duplex communication between the UFS host 2100 and the UFS device 2200 may be performed by a structure in which the reception lane is separated from the transmission lane. Thus, the UFS device 2200 may transmit data to the UFS host 2100 through the transmission lane even while receiving data from the UFS host 2100 through the reception lane. In addition, control data such as a command from the UFS host 2100 to the UFS device 2200 and user data to be stored in or read from the NVM storage 2220 in the UFS device 2200 may be transmitted through the same lane. Thus, a separate lane for data transmission may not be provided between the UFS host 2100 and the UFS device 2200 besides the reception lane and the transmission lane.

The UFS device controller 2210 in the UFS device 2200 may generally control an operation of the UFS device 2200. The UFS device controller 2210 may manage the NVM storage 2220 through logical units (LUs) 2211, which are logical data storage units. The number of LUs 2211 may be 8 but is not limited thereto. The UFS device controller 2210 may include a flash translation layer (FTL) and may translate a logical data address, e.g., a logical block address (LBA), transmitted from the UFS host 2100 into a physical data address, e.g., a physical block address (PBA), by using address mapping information of the FTL. A logical block for storage of user data in the UFS system 2000 may have a size of a certain range. For example, a minimum size of the logical block may be set to 4 Kbytes.

When a command from the UFS host 2100 is input to the UFS device 2200 through the UIC layer 2250, the UFS device controller 2210 may perform an operation according to the input command and transmit, when the operation is completed, a completion response to the UFS host 2100.

For example, when the UFS host 2100 desires to store user data in the UFS device 2200, the UFS host 2100 may transmit a data write command to the UFS device 2200. When a ready-to-transfer response indicating ready to receive the user data is received from the UFS device 2200, the UFS host 2100 may transmit the user data to the UFS device 2200. The UFS device controller 2210 may temporarily store the received user data in the device memory 2240, and may store the user data, temporarily stored in the device memory 2240, in a selected location of the NVM storage 2220 based on the address mapping information of the FTL.

As another example, when the UFS host 2100 desires to read user data stored in the UFS device 2200, the UFS host 2100 may transmit a data read command to the UFS device 2200. The UFS device controller 2210, which has received the data read command, may read the user data from the NVM storage 2220 based on the data read command and temporarily store the read user data in the device memory 2240. In this read process, the UFS device controller 2210 may detect an error of the read user data and correct the detected error, e.g., by using an embedded error correction code (ECC) circuit (not shown). Thereafter, the UFS device controller 2210 may transmit the user data, temporarily stored in the device memory 2240, to the UFS host 2100. In addition, the UFS device controller 2210 may further include an advanced encryption standard (AES) circuit (not shown), and the AES circuit may encrypt or decrypt data, input to the UFS device controller 2210, by using a symmetric-key algorithm.

The UFS host 2100 may sequentially store commands, to be transmitted to the UFS device 2200, in the UFS host register 2111, which may function as a CQ, and transmit the commands to the UFS device 2200 in the storage sequence. In this case, even when a previously transmitted command is being processed by the UFS device 2200, i.e., even when a notification indicating that the previously transmitted command is completely processed by the UFS device 2200 is not received, the UFS host 2100 may transmit a subsequent command buffered in the CQ to the UFS device 2200, and thus the UFS device 2200 may also receive the subsequent command from the UFS host 2100 even while processing the previously transmitted command. A maximum number (queue depth) of commands, which may be stored in the CQ, may be, e.g., 32. In addition, the CQ may be implemented in a circular queue type in which a start point and an end point of a command string stored in the CQ are respectively indicated by a head pointer and a tail pointer.

Each of the plurality of storage units 2221 may include a memory cell array and a control circuit configured to control an operation of the memory cell array. The memory cell array may include a 2D or 3D memory cell array. The memory cell array may include a plurality of memory cells, and each memory cell may be a single level cell (SLC) in which one-bit information is stored, or a cell in which two-or-more-bit information is stored, such as a multi-level cell (MLC), a triple level cell (TLC), or a quadruple level cell (QLC). The 3D memory cell array may include a V-NAND string vertically oriented so that at least one memory cell is located on another memory cell.

Power source voltages such as VCC, VCCQ1, and VCCQ2 may be input to the UFS device 2200. VCC may be a main power source voltage for the UFS device 2200 and may have a value of about 2.4 V to about 3.6 V. VCCQ1 may be a power source voltage for supplying a low-level voltage, e.g., for the UFS device controller 2210, and may have a value of about 1.14 V to about 1.26 V. VCCQ2 may be a power source voltage for supplying a voltage of a level lower than VCC but higher than VCCQ1, e.g., for an input-output interface such as the MIPI M-PHY 2251, and may have a value of about 1.7 V to about 1.95 V. The power source voltages may be supplied to each component in the UFS device 2200 through the regulator 2260. The regulator 2260 may be implemented by a set of unit regulators respectively connected to the power source voltages described above.

FIGS. 13A to 13C are diagrams for describing a form factor of a UFS card. When the UFS device 2200 described with reference to FIG. 12 is implemented in a form of a UFS card 4000, the exterior appearance of the UFS card 4000 may be as shown in FIGS. 13A to 13C.

FIG. 13A is a top view of the UFS card 4000. Referring to FIG. 13A, the UFS card 4000 may have a shape or design like a shark fin. In FIG. 13A, the UFS card 4000 may have, e.g., dimensions shown in Table 1 below.

TABLE 1 Item Dimension (mm) T1 9.70 T2 15.00 T3 11.00 T4 9.70 T5 5.15 T6 0.25 T7 0.60 T8 0.75 T9 0.80 (R)

FIG. 13B is a side view of the UFS card 4000. In FIG. 13B, the UFS card 4000 may have, e.g., dimensions shown in Table 2 below.

TABLE 2 Item Dimension (mm) S1 0.74 ± 0.06 S2 0.30 S3 0.52 S4 1.20 S5 1.05 S6 1.00

FIG. 13C is a bottom view of the UFS card 4000. Referring to FIG. 13C, a plurality of pins for an electrical contact with a UFS slot may be formed on a bottom surface of the UFS card 4000, and a function of each pin will be described below. By symmetry between a top surface and the bottom surface of the UFS card 4000, some (e.g., T1 to T5 and T9) of the information about the dimensions described with reference to FIG. 13A and Table 1 may also be applied to the bottom view of the UFS card 4000 as shown in FIG. 13C.

The plurality of pins for an electrical connection with a UFS host may be formed on the bottom surface of the UFS card 4000, and according to FIG. 13C, a total number of pins may be 12. Each pin may have a rectangular shape, and a signal name corresponding to each pin may be as shown in FIG. 13C. Brief information of each pin may refer to Table 3 below and may also refer to the description made above with reference to FIG. 12 .

TABLE 3 Number Signal name Description Dimension (mm) 1 VSS Ground (GND) 3.00 × 0.72 ± 0.05 2 DIN_C Differential input signal input from a host to 1.50 × 0.72 ± 0.05 3 DIN_T the UFS card 4000 (DIN_C denotes a negative node, and DIN_T denotes a positive node) 4 VSS Same as number 1 3.00 × 0.72 ± 0.05 5 DOUT_C Differential output signal output from the UFS 1.50 × 0.72 ± 0.05 6 DOUT_T card 4000 to a host (DOUT_C denotes a negative node, and DOUT_T denotes a positive node) 7 VSS Same as number 1 3.00 × 0.72 ± 0.05 8 REF_CLK Reference clock provided from a host to the 1.50 × 0.72 ± 0.05 UFS card 4000 9 VCCQ2 Power source voltage having a relatively lower 3.00 × 0.72 ± 0.05 value than VCC, which is mainly provided for a PHY interface or a controller 10 C/D(GND) Signal for card detection 1.50 × 0.72 ± 0.05 11 VSS Same as number 1 3.00 × 0.80 ± 0.05 12 Vcc Main power source voltage

FIG. 14 is a block diagram of a NVM storage 2220 a according to an example embodiment.

Referring to FIG. 14 , the NVM storage 2220 a may include a memory device 2224 and a memory controller 2222. The NVM storage 2220 a may support a plurality of channels, e.g., first to mth channels CH1 to CHm, and the memory device 2224 and the memory controller 2222 may be connected to each other through the first to mth channels CH1 to CHm. For example, the NVM storage 2220 a may be implemented by a storage device such as an SSD.

The memory device 2224 may include a plurality of NVM devices NVM11 to NVMmn. Each of the plurality of NVM devices NVM11 to NVMmn may be connected to one of the first to mth channels CH1 to CHm through a corresponding way. For example, the NVM devices NVM11 to NVM1 n may be connected to the first channel CH1 through ways W11 to W1 n, respectively, and the NVM devices NVM21 to NVM2 n may be connected to the second channel CH2 through ways W21 to W2 n, respectively. In an example embodiment, each of the plurality of NVM devices NVM11 to NVMmn may be implemented in random memory units operable according to an individual command from the memory controller 2222. For example, each of the plurality of NVM devices NVM11 to NVMmn may be implemented by a chip or a die, but embodiments are not limited thereto.

The memory controller 2222 may transmit and receive signals to and from the memory device 2224 through the first to mth channels CH1 to CHm. For example, the memory controller 2222 may transmit commands CMDa˜CMDm, addresses ADDRa˜ADDRm, and data DATAa˜DATAm to the memory device 2224 or receive the data DATAa˜DATAm from the memory device 2224, through the first to mth channels CH1 to CHm.

The memory controller 2222 may select, through a corresponding channel, one of NVM devices connected to the corresponding channel, and transmit and receive signals to and from the selected NVM device. For example, the memory controller 2222 may select the NVM device NVM11 from among the NVM devices NVM11 to NVM1 n connected to the first channel CH1. The memory controller 2222 may transmit the command CMDa, the address ADDRa, and the data DATAa to the selected NVM device NVM11, or receive the data DATAa from the selected NVM device NVM11, through the first channel CH1.

The memory controller 2222 may transmit and receive signals to and from the memory device 2224 in parallel through different channels. For example, the memory controller 2222 may transmit the command CMDb to the memory device 2224 through the second channel CH2 while transmitting the command CMDa to the memory device 2224 through the first channel CH1. For example, the memory controller 2222 may receive the data DATAb from the memory device 2224 through the second channel CH2 while receiving the data DATAa from the memory device 2224 through the first channel CH1.

The memory controller 2222 may control a general operation of the memory device 2224. The memory controller 2222 may control each of the plurality of NVM devices NVM11 to NVMmn connected to the first to mth channels CH1 to CHm by transmitting a signal through the first to mth channels CH1 to CHm. For example, the memory controller 2222 may control one selected from among the NVM devices NVM11 to NVM1 n, by transmitting the command CMDa and the address ADDRa through the first channel CH1.

Each of the plurality of NVM devices NVM11 to NVMmn may be operated under control of the memory controller 2222. For example, the NVM device NVM11 may program the data DATAa according to the command CMDa, the address ADDRa, and the data DATAa provided through the first channel CH1. For example, the nonvolatile memory device NVM21 may read the data DATAb according to the command CMDb and the address ADDRb provided through the second channel CH2 and transmit the read data DATAb to the memory controller 2222.

Although FIG. 14 shows that the memory device 2224 communicates with the memory controller 2222 through m channels and includes n NVM devices in correspondence to each channel, the number of channels and the number of NVM devices connected to one channel may be variously changed.

FIG. 15 is a block diagram of an NVM storage 2220 b according to an example embodiment. Referring to FIG. 15 , the NVM storage 2220 b may include a memory device 2226 and the memory controller 2222. The memory device 2226 may correspond to one of the plurality of NVM devices NVM11 to NVMmn, which communicates with the memory controller 2222 based on one of the first to mth channels CH1 to CHm of FIG. 14 . The memory controller 2222 may correspond to the memory controller 2222 of FIG. 14 .

The memory device 2226 may include first to eighth pins P11 to P18, a memory interface circuit 2310, a control logic circuit 2320, and a memory cell array 2330.

The memory interface circuit 2310 may receive a chip enable signal nCE from the memory controller 2222 through the first pin P11. The memory interface circuit 2310 may transmit and receive signals to and from the memory controller 2222 through the second to eighth pins P12 to P18 in response to the chip enable signal nCE. For example, when the chip enable signal nCE is in an enable state (e.g., a low level), the memory interface circuit 2310 may transmit and receive signals to and from the memory controller 2222 through the second to eighth pins P12 to P18.

The memory interface circuit 2310 may receive a command latch enable signal CLE, an address latch enable signal ALE, and a write enable signal nWE from the memory controller 2222 through the second to fourth pins P12 to P14, respectively. The memory interface circuit 2310 may receive or transmit a data signal DQ from or to the memory controller 2222 through the seventh pin P17. A command CMD, an address ADDR, and data DATA may be delivered through the data signal DQ. For example, the data signal DQ may be delivered through a plurality of data signal lines. In this case, the seventh pin P17 may include a plurality of pins corresponding to the plurality of data signal lines.

The memory interface circuit 2310 may obtain the command CMD from the data signal DQ received in an enable period (e.g., a high-level state) of the command latch enable signal CLE based on toggle timings of the write enable signal nWE. The memory interface circuit 2310 may obtain the address ADDR from the data signal DQ received in an enable period (e.g., a high-level state) of the address latch enable signal ALE based on toggle timings of the write enable signal nWE.

In an example embodiment, the write enable signal nWE may maintain a static state (e.g., a high level or a low level) and then toggle between the high level and the low level. For example, the write enable signal nWE may toggle in a period in which the command CMD or the address ADDR is transmitted. Thus, the memory interface circuit 2310 may obtain the command CMD or the address ADDR based on toggle timings of the write enable signal nWE.

The memory interface circuit 2310 may receive a read enable signal nRE from the memory controller 2222 through the fifth pin P15. The memory interface circuit 2310 may receive or transmit a data strobe signal DQS from or to the memory controller 2222 through the sixth pin P16.

In a data output operation of the memory device 2226, the memory interface circuit 2310 may receive the read enable signal nRE, which toggles, through the fifth pin P15 before outputting the data DATA. The memory interface circuit 2310 may generate the data strobe signal DQS, which toggles based on the toggling of the read enable signal nRE. For example, the memory interface circuit 2310 may generate the data strobe signal DQS, which starts to toggle after a pre-defined delay (e.g., t_(DQSRE)) from a toggling start time of the read enable signal nRE. The memory interface circuit 2310 may transmit the data signal DQ including the data DATA based on toggle timing of the data strobe signal DQS. Thus, the data DATA may be aligned with the toggle timing of the data strobe signal DQS and transmitted to the memory controller 2222.

In a data input operation of the memory device 2226, when the data signal DQ including the data DATA is received from the memory controller 2222, the memory interface circuit 2310 may receive the data strobe signal DQS, which toggles, together with the data DATA from the memory controller 2222. The memory interface circuit 2310 may obtain the data DATA from the data signal DQ based on toggle timing of the data strobe signal DQS. For example, the memory interface circuit 2310 may obtain the data DATA by sampling the data signal DQ at a leading edge and a trailing edge of the data strobe signal DQS.

The memory interface circuit 2310 may transmit a ready/busy output signal nR/B to the memory controller 2222 through the eighth pin P18. The memory interface circuit 2310 may transmit state information of the memory device 2226 to the memory controller 2222 through the ready/busy output signal nR/B. When the memory device 2226 is in a busy state (i.e., while performing internal operations of the memory device 2226), the memory interface circuit 2310 may transmit the ready/busy output signal nR/B indicating the busy state to the memory controller 2222. When the memory device 2226 is in a ready state (i.e., when internal operations of the memory device 2226 are not performed or are completed), the memory interface circuit 2310 may transmit the ready/busy output signal nR/B indicating the ready state to the memory controller 2222. For example, while the memory device 2226 is reading the data DATA from the memory cell array 2330 in response to a page read command, the memory interface circuit 2310 may transmit the ready/busy output signal nR/B indicating the busy state (e.g., the low level) to the memory controller 2222. For example, while the memory device 2226 is programming the data DATA to the memory cell array 2330 in response to a program command, the memory interface circuit 2310 may transmit the ready/busy output signal nR/B indicating the busy state to the memory controller 2222.

The control logic circuit 2320 may generally control various kinds of operations of the memory device 2226. The control logic circuit 2320 may receive the command/address CMD/ADDR from the memory interface circuit 2310. The control logic circuit 2320 may generate control signals for controlling the other components in the memory device 2226, in response to the received command/address CMD/ADDR. For example, the control logic circuit 2320 may generate various kinds of control signals for programming or reading the data DATA to or from the memory cell array 2330.

The memory cell array 2330 may store the data DATA obtained from the memory interface circuit 2310, under control of the control logic circuit 2320. The memory cell array 2330 may output the stored data DATA to the memory interface circuit 2310 under control of the control logic circuit 2320.

The memory cell array 2330 may include a plurality of memory cells. For example, the plurality of memory cells may be flash memory cells. However, embodiments are not limited thereto, and the plurality of memory cells may be RRAM cells, ferroelectric random access memory (FRAM) cells, PRAM cells, thyristor random access memory (TRAM) cells, or MRAM cells. Hereinafter, example embodiments will be described based on an embodiment in which the plurality of memory cells are NAND flash memory cells.

The memory controller 2222 may include first to eighth pins P21 to P28 and a controller interface circuit 2410. The first to eighth pins P21 to P28 may correspond to the first to eighth pins P11 to P18 in the memory device 2226.

The controller interface circuit 2410 may transmit the chip enable signal nCE to the memory device 2226 through the first pin P21. The controller interface circuit 2410 may transmit and receive, through the second to eighth pins P22 to P28, signals to and from the memory device 2226 selected based on the chip enable signal nCE.

The controller interface circuit 2410 may transmit the command latch enable signal CLE, the address latch enable signal ALE, and the write enable signal nWE to the memory device 2226 through the second to fourth pins P22 to P24, respectively. The controller interface circuit 2410 may transmit or receive the data signal DQ to or from the memory device 2226 through the seventh pin P27.

The controller interface circuit 2410 may transmit, to the memory device 2226, the data signal DQ including the command CMD or the address ADDR together with the write enable signal nWE, which toggles. The controller interface circuit 2410 may transmit the data signal DQ including the command CMD to the memory device 2226 according to transmission of the command latch enable signal CLE having an enable state, and transmit the data signal DQ including the address ADDR to the memory device 2226 according to transmission of the address latch enable signal ALE having an enable state.

The controller interface circuit 2410 may transmit the read enable signal nRE to the memory device 2226 through the fifth pin P25. The controller interface circuit 2410 may receive or transmit the data strobe signal DQS from or to the memory device 2226 through the sixth pin P26.

In a data output operation of the memory device 2226, the controller interface circuit 2410 may generate the read enable signal nRE, which toggles, and transmit the read enable signal nRE to the memory device 2226. For example, the controller interface circuit 2410 may generate the read enable signal nRE, which changes from the static state (e.g., the high level or the low level) to a toggle state, before the data DATA is output. Thus, the memory device 2226 may generate the data strobe signal DQS, which toggles based on the read enable signal nRE. The controller interface circuit 2410 may receive, from the memory device 2226, the data signal DQ including the data DATA together with the data strobe signal DQS, which toggles. The controller interface circuit 2410 may obtain the data DATA from the data signal DQ based on toggle timing of the data strobe signal DQS.

In a data input operation of the memory device 2226, the controller interface circuit 2410 may generate the data strobe signal DQS, which toggles. For example, the controller interface circuit 2410 may generate the data strobe signal DQS, which changes from the static state (e.g., the high level or the low level) to the toggle state, before the data DATA is transmitted. The controller interface circuit 2410 may transmit the data signal DQ including the data DATA to the memory device 2226 based on toggle timings of the data strobe signal DQS.

The controller interface circuit 2410 may receive the ready/busy output signal nR/B from the memory device 2226 through the eighth pin P28. The controller interface circuit 2410 may determine state information of the memory device 2226 based on the ready/busy output signal nR/B.

FIG. 16 is a block diagram of the memory device 2226 of FIG. 15 . Referring to FIG. 16 , the memory device 2226 may include the control logic circuit 2320, the memory cell array 2330, a page buffer unit 2340, a voltage generator 2350, and a row decoder 3394. Although not shown in FIG. 16 , the memory device 2226 may further include the memory interface circuit 2310 shown in FIG. 15 and in addition, the memory device 2226 may further include a column logic, a pre-decoder, a temperature sensor, a command decoder, an address decoder, and the like.

The control logic circuit 2320 may generally control various kinds of operations of the memory device 2226. The control logic circuit 2320 may output various kinds of control signals in response to the command CMD and/or the address ADDR from the memory interface circuit 2310. For example, the control logic circuit 2320 may output a voltage control signal CTRL_vol, a row address X-ADDR, and a column address Y-ADDR.

The memory cell array 2330 may include a plurality of memory blocks BLK1 to BLKz (z is a positive integer), and each of the plurality of memory blocks BLK1 to BLKz may include a plurality of memory cells. The memory cell array 2330 may be connected to the page buffer unit 2340 through bit lines BL and connected to the row decoder 3394 through word lines WL, string select lines SSL, and ground select lines GSL.

In an example embodiment, the memory cell array 2330 may include a 3D memory cell array, and the 3D memory cell array may include a plurality of NAND strings. Each NAND string may include memory cells respectively connected to word lines vertically stacked on a substrate. U.S. Pat. Nos. 7,679,133, 8,553,466, 8,654,587, and 8,559,235 and U.S. Patent Application Publication No. 2011/0233648 are herein incorporated in their entirety by reference. In an example embodiment, the memory cell array 2330 may include a 2D memory cell array, and the 2D memory cell array may include a plurality of NAND strings arranged in row and column directions.

The page buffer unit 2340 may include a plurality of page buffers PB1 to PBn (n is an integer greater than or equal to 3), and the plurality of page buffers PB1 to PBn may be connected to memory cells through a plurality of bit lines BL, respectively. The page buffer unit 2340 may select at least one bit line BL from among the plurality of bit lines BL in response to the column address Y-ADDR. The page buffer unit 2340 may operate as a write driver or a sense amplifier according to an operation mode. For example, in a program operation, the page buffer unit 2340 may apply, to a selected bit line BL, a bit line voltage corresponding to data to be programmed. In a read operation, the page buffer unit 2340 may sense data stored in a memory cell by sensing a current or a voltage of a selected bit line BL.

The voltage generator 2350 may generate various types of voltages for performing program, read, and discard operations based on the voltage control signal CTRL_vol. For example, the voltage generator 2350 may generate a program voltage, a read voltage, a program verify voltage, a discard voltage, or the like as a word line voltage VWL.

The row decoder 3394 may select one of a plurality of word lines WL in response to the row address X-ADDR and select one of a plurality of string select lines SSL. For example, in a program operation, the row decoder 3394 may apply the program voltage and the program verify voltage to a selected word line WL, and in a read operation, the row decoder 3394 may apply the read voltage to a selected word line WL.

FIG. 17 is a diagram for describing a 3D V-NAND structure applicable to a UFS device, according to an example embodiment. When a storage module in the UFS device is implemented by 3D V-NAND-type flash memory, each of a plurality of memory blocks included in the storage module may be represented by an equivalent circuit as shown in FIG. 17 . A memory block BLKi shown in FIG. 17 indicates a 3D memory block formed in a 3D structure. A plurality of memory NAND strings in the memory block BLKi may be formed in a direction vertical to a substrate.

Referring to FIG. 17 , the memory block BLKi may include a plurality of memory NAND strings NS11 to NS33 connected between bit lines BL1, BL2, and BL3 and a common source line CSL. Each of the plurality of memory NAND strings NS11 to NS33 may include a string select transistor SST, a plurality of memory cells MC1, MC2, . . . , MC8, and a ground select transistor GST. Although FIG. 17 shows that each of the plurality of memory NAND strings NS11 to NS33 includes eight memory cells MC1, MC2, . . . , MC8, embodiments are not limited thereto.

The string select transistor SST may be connected to a corresponding string select line SSL1, SSL2, or SSL3. The plurality of memory cells MC1, MC2, . . . , MC8 may be connected to corresponding gate lines GTL1, GTL2, . . . , GTL8, respectively. The gate lines GTL1, GTL2, . . . GTL8 may correspond to word lines, and some of the gate lines GTL1, GTL2, . . . , GTL8 may correspond to dummy word lines. The ground select transistor GST may be connected to a corresponding ground select line GSL1, GSL2, or GSL3. The string select transistor SST may be connected to a corresponding bit line BL1, BL2, or BL3, and the ground select transistor GST may be connected to the common source line CSL.

A word line (e.g., WL1) of the same height may be commonly connected, and the ground select lines GSL1, GSL2, and GSL3 and the string select lines SSL1, SSL2, and SSL3 may be individually separated. Although FIG. 17 shows that the memory block BLKi is connected to eight gate lines GTL1, GTL2, . . . , GTL8 and three bit lines BL1, BL2, and BL3, embodiments are not limited thereto.

FIG. 18 is a cross-sectional view of a bonding vertical NAND (BVNAND) structure applicable to a UFS device, according to an example embodiment.

Referring to FIG. 18 , a memory device 2226 may have a chip-to-chip (C2C) structure. The C2C structure may refer to a structure formed by manufacturing an upper chip including a cell region CELL on a first wafer, manufacturing a lower chip including a peripheral circuit region PERI on a second wafer, separate from the first wafer, and then bonding the upper chip and the lower chip to each other. Here, the bonding process may include a method of electrically connecting a bonding metal formed on an uppermost metal layer of the upper chip and a bonding metal formed on an uppermost metal layer of the lower chip. For example, when the bonding metals include copper (Cu), the upper and lower chips may be bonded together using a Cu-to-Cu bonding. The present example embodiment, however, is not limited thereto. For example, the bonding metals may also be formed of aluminum (Al) or tungsten (W).

Each of the peripheral circuit region PERI and the cell region CELL of the memory device 2226 may include an external pad bonding area PA, a word line bonding area WLBA, and a bit line bonding area BLBA.

The peripheral circuit region PERI may include a first substrate 3210, an interlayer insulating layer 3215, a plurality of circuit elements 3220 a, 3220 b, and 3220 c formed on the first substrate 3210, first metal layers 3230 a, 3230 b, and 3230 c respectively connected to the plurality of circuit elements 3220 a, 3220 b, and 3220 c, and second metal layers 3240 a, 3240 b, and 3240 c formed on the first metal layers 3230 a, 3230 b, and 3230 c. The first metal layers 3230 a, 3230 b, and 3230 c may be formed of tungsten having relatively high electrical resistivity, and the second metal layers 3240 a, 3240 b, and 3240 c may be formed of copper having relatively low electrical resistivity.

In FIG. 18 , although only the first metal layers 3230 a, 3230 b, and 3230 c and the second metal layers 3240 a, 3240 b, and 3240 c are shown, one or more additional metal layers may be further formed on the second metal layers 3240 a, 3240 b, and 3240 c. At least a portion of the one or more additional metal layers formed on the second metal layers 3240 a, 3240 b, and 3240 c may be formed of aluminum or the like having a lower electrical resistivity than those of copper forming the second metal layers 3240 a, 3240 b, and 3240 c.

The interlayer insulating layer 3215 may be disposed on the first substrate 3210, and may cover the plurality of circuit elements 3220 a, 3220 b, and 3220 c, the first metal layers 3230 a, 3230 b, and 3230 c, and the second metal layers 3240 a, 3240 b, and 3240 c. The interlayer insulating layer 3215 may include an insulating material such as silicon oxide, silicon nitride, or the like.

Lower bonding metals 3271 b and 3272 b may be formed on the second metal layer 3240 b in the word line bonding area WLBA. In the word line bonding area WLBA, the lower bonding metals 3271 b and 3272 b in the peripheral circuit region PERI may be electrically bonded to upper bonding metals 3371 b and 3372 b of the cell region CELL. The lower bonding metals 3271 b and 3272 b and the upper bonding metals 3371 b and 3372 b may be formed of aluminum, copper, tungsten, or the like. The upper bonding metals 3371 b and 3372 b in the cell region CELL may be referred as first metal pads. The lower bonding metals 3271 b and 3272 b in the peripheral circuit region PERI may be referred as second metal pads.

The cell region CELL may include at least one memory block. The cell region CELL may include a second substrate 3310 and a common source line 3320. On the second substrate 3310, a plurality of word lines 3331 to 3338 (i.e., 3330) may be stacked in a direction (a Z-axis direction), perpendicular to an upper surface of the second substrate 3310. At least one string select line and at least one ground select line may be arranged on and below the plurality of word lines 3330, respectively, and the plurality of word lines 3330 may be disposed between the at least one string select line and the at least one ground select line.

In the bit line bonding area BLBA, a channel structure CH may extend in a direction (a Z-axis direction), perpendicular to the upper surface of the second substrate 3310, and pass through the plurality of word lines 3330, the at least one string select line, and the at least one ground select line. The channel structure CH may include a data storage layer, a channel layer, a buried insulating layer, and the like. The channel layer may be electrically connected to a first metal layer 3350 c and a second metal layer 3360 c. For example, the first metal layer 3350 c may be a bit line contact, and the second metal layer 3360 c may be a bit line. The bit line 3360 c may extend in a first direction (a Y-axis direction), parallel to the upper surface of the second substrate 3310.

In FIG. 18 , an area in which the channel structure CH, the bit line 3360 c, and the like are disposed may be defined as the bit line bonding area BLBA. In the bit line bonding area BLBA, the bit line 3360 c may be electrically connected to the circuit elements 3220 c (which may provide a page buffer 3393) in the peripheral circuit region PERI. The bit line 3360 c may be connected to upper bonding metals 3371 c and 3372 c in the cell region CELL. The upper bonding metals 3371 c and 3372 c may be connected to lower bonding metals 3271 c and 3272 c connected to the circuit elements 3220 c of the page buffer 3393.

In the word line bonding area WLBA, the plurality of word lines 3330 may extend in a second direction (an X-axis direction), parallel to the upper surface of the second substrate 3310 and perpendicular to the first direction, and may be connected to a plurality of cell contact plugs 3341 to 3347 (i.e., 3340). The plurality of word lines 3330 and the plurality of cell contact plugs 3340 may be connected to each other in pads provided by at least a portion of the plurality of word lines 3330 extending in different lengths in the second direction. A first metal layer 3350 b and a second metal layer 3360 b may be connected to an upper portion of the plurality of cell contact plugs 3340 connected to the plurality of word lines 3330, sequentially. The plurality of cell contact plugs 3340 may be connected to the peripheral circuit region PERI by the upper bonding metals 3371 b and 3372 b of the cell region CELL and the lower bonding metals 3271 b and 3272 b of the peripheral circuit region PERI in the word line bonding area WLBA.

The plurality of cell contact plugs 3340 may be electrically connected to the circuit elements 3220 b forming a row decoder 3394 in the peripheral circuit region PERI. In an example embodiment, operating voltages of the circuit elements 3220 b of the row decoder 3394 may be different than operating voltages of the circuit elements 3220 c forming the page buffer 3393. For example, operating voltages of the circuit elements 3220 c forming the page buffer 3393 may be greater than operating voltages of the circuit elements 3220 b forming the row decoder 3394.

A common source line contact plug 3380 may be disposed in the external pad bonding area PA. The common source line contact plug 3380 may be formed of a conductive material such as a metal, a metal compound, polysilicon, or the like, and may be electrically connected to the common source line 3320. A first metal layer 3350 a and a second metal layer 3360 a may be stacked on an upper portion of the common source line contact plug 3380, sequentially. An area in which the common source line contact plug 3380, the first metal layer 3350 a, and the second metal layer 3360 a are disposed may be defined as the external pad bonding area PA.

Input-output pads 3205 and 3305 may be disposed in the external pad bonding area PA. Referring to FIG. 18 , a lower insulating film 3201 covering a lower surface of the first substrate 3210 may be formed below the first substrate 3210, and a first input-output pad 3205 may be formed on the lower insulating film 3201. The first input-output pad 3205 may be connected to at least one of the plurality of circuit elements 3220 a, 3220 b, and 3220 c disposed in the peripheral circuit region PERI through a first input-output contact plug 3203, and may be separated from the first substrate 3210 by the lower insulating film 3201. In addition, a side insulating film may be disposed between the first input-output contact plug 3203 and the first substrate 3210 to electrically separate the first input-output contact plug 3203 and the first substrate 3210.

An upper insulating film 3301 covering the upper surface of the second substrate 3310 may be formed on the second substrate 3310, and a second input-output pad 3305 may be disposed on the upper insulating film 3301. The second input-output pad 3305 may be connected to at least one of the plurality of circuit elements 3220 a, 3220 b, and 3220 c disposed in the peripheral circuit region PERI through a second input-output contact plug 3303. The second input-output pad 3305 may be electrically connected to a circuit element 3220 a.

The second substrate 3310 and the common source line 3320 may not be disposed in an area in which the second input-output contact plug 3303 is disposed. The second input-output pad 3305 may not overlap the word lines 3330 in the third direction (the Z-axis direction). The second input-output contact plug 3303 may be separated from the second substrate 3310 in a direction, parallel to the upper surface of the second substrate 3310, and may pass through the interlayer insulating layer 3315 of the cell region CELL to be connected to the second input-output pad 3305.

In an example embodiment, the first input-output pad 3205 and the second input-output pad 3305 may be selectively formed. For example, the memory device 2226 may include only the first input-output pad 3205 disposed on the first substrate 3210 or the second input-output pad 3305 disposed on the second substrate 3310. Alternatively, the memory device 2226 may include both the first input-output pad 3205 and the second input-output pad 3305.

A metal pattern provided on an uppermost metal layer may be provided as a dummy pattern or the uppermost metal layer may be absent, in each of the external pad bonding area PA and the bit line bonding area BLBA, respectively included in the cell region CELL and the peripheral circuit region PERI.

In the external pad bonding area PA, the memory device 2226 may include a lower metal pattern 3273 a, corresponding to an upper metal pattern 3372 a formed in an uppermost metal layer of the cell region CELL, and having the same cross-sectional shape as the upper metal pattern 3372 a of the cell region CELL so as to be connected to each other, in an uppermost metal layer of the peripheral circuit region PERI. In the peripheral circuit region PERI, the lower metal pattern 3273 a formed in the uppermost metal layer of the peripheral circuit region PERI may not be connected to a contact. Similarly, in the external pad bonding area PA, an upper metal pattern 3372 a, corresponding to the lower metal pattern 3273 a formed in an uppermost metal layer of the peripheral circuit region PERI, and having the same shape as a lower metal pattern 3273 a of the peripheral circuit region PERI, may be formed in an uppermost metal layer of the cell region CELL.

The lower bonding metals 3271 b and 3272 b may be formed on the second metal layer 3240 b in the word line bonding area WLBA. In the word line bonding area WLBA, the lower bonding metals 3271 b and 3272 b of the peripheral circuit region PERI may be electrically connected to the upper bonding metals 3371 b and 3372 b of the cell region CELL by Cu-to-Cu bonding.

In the bit line bonding area BLBA, an upper metal pattern 3392 (corresponding to a lower metal pattern 3252 formed in the uppermost metal layer of the peripheral circuit region PERI, and having the same cross-sectional shape as the lower metal pattern 3252 of the peripheral circuit region PERI) may be formed in an uppermost metal layer of the cell region CELL. A contact may not be formed on the upper metal pattern 3392 formed in the uppermost metal layer of the cell region CELL.

A reinforcement metal pattern (corresponding to a metal pattern formed in an uppermost metal layer in one of the cell region CELL and the peripheral circuit region PERI) having the same cross-sectional shape as the metal pattern may be formed in an uppermost metal layer in the other one of the cell region CELL and the peripheral circuit region PERI. A contact may not be formed on the reinforcement metal pattern.

By way of summation and review, a storage device may provide a host with a protected region for storing data that is intended to remain secure, and may permit only authenticated access to the protected region. Attacks may be made on the storage device and/or the host to acquire and/or change data stored in the protected region, or to insert an error in access to the protected region. Therefore, it may be desirable to securely authenticate access to, and operations in, the protected region.

A storage device using an interface such as a universal flash storage (UFS) or an embedded multi-media card (eMMC) may define a relay protected memory block (RPMB) as a region that is protected from a relay attack. A host may store, in the RPMB, data that is intended to remain secure. The storage device may allow only an authenticated access to the RPMB. A write count and a nonce may be used to authenticate an access to the RPMB. Example embodiments may use a nonce to protect a data write operation with respect to an RPMB from MITM attacks, rather than using a nonce only for a read operation with respect to an RPMB, and thus an access to an RPMB may be protected from MITM attacks. The host may generate a nonce for a write request, and provide the write request including the generated nonce to the storage device. The storage device may verify the write request based on the nonce included in the write request. When a nonce included in a previous write request is identical to a nonce included in a current write request, the storage device may determine a failure of verification of the current write request. The storage device may provide the host with a response including the nonce extracted from the write request, and the host may verify an MAC and determine whether the nonce included in the response is identical to a nonce having been included in the write request, while verifying the response.

As described above, embodiments may provide a system, device, and method for protecting data from being written to a protected region by attacks.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Thus, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims. 

What is claimed is:
 1. A method of writing data to a protected region in response to a request from a host, the method comprising: providing, to the host, a device write count; receiving, from the host, a first write request including a first host message authentication code and a first random number, the first host message authentication code being based on a host write count, which is set to be the same as the device write count, and the first random number; verifying the first write request based on the device write count and the host write count, the first random number, and the first host message authentication code; updating the device write count based on a result of verifying the first write request, the updating of the device write count including incrementing the device write count when the verifying of the first write request succeeds; generating a first device message authentication code based on the updated device write count and the first random number; and providing the host with a first response including the first device message authentication code and the result of verifying the first write request, wherein the first response further includes the first random number.
 2. The method as claimed in claim 1, wherein the updating of the device write count includes: maintaining the device write count, when the verifying of the first write request fails.
 3. The method as claimed in claim 1, further comprising: receiving a second write request including a second host message authentication code, a second host write count, and a second random number from the host; and verifying the second write request based on the updated device write count, the second random number, and the second host message authentication code.
 4. The method as claimed in claim 3, further comprising: generating a second device message authentication code based on the updated device write count and the second random number; and providing the host with a second response including the second device message authentication code and a result of the verifying of the second write request.
 5. The method as claimed in claim 1, wherein the verifying of the first write request includes: generating a first host message verification code based on the device write count and the first random number; and comparing the first host message verification code with the first host message authentication code.
 6. The method as claimed in claim 5, wherein: the first write request includes a first host write count, and the verifying of the first write request further includes comparing the device write count with the first host write count.
 7. The method as claimed in claim 5, wherein: the generating of the first host message verification code is based on a key shared with the host in advance, the device write count, and the first random number, and the generating of the first device message authentication code is based on the key, the updated write count, and the first random number.
 8. A storage device configured to communicate with a host, the storage device comprising: a memory including a protected region; and a controller, wherein the controller is configured to: provide, to the host, a device write count, receive, from the host, a first write request including a first host message authentication code and a first random number, the first host message authentication code being based on a host write count, which is set to be the same as the device write count, and the first random number, verify the first write request based on the device write count and the host write count, the first random number, and the first host message authentication code, write data included in the first write request to the protected region when the verifying of the first write request succeeds, update the device write count based on a result of verifying the first write request, the updating of the device write count including incrementing the device write count when the verifying of the first write request succeeds, generate a first device message authentication code based on the updated write count and the first random number, and provide the host with a first response including the first device message authentication code and the result of verifying the first write request, wherein the first response further includes the first random number.
 9. The storage device as claimed in claim 8, wherein the controller is further configured to verify the first write request by generating a first host message verification code based on the device write count and the first random number, and comparing the first host message verification code with the first host message authentication code.
 10. A method of writing data to a storage device including a protected region, the method comprising: receiving, at a host, a device write count from the storage device, and setting a host write count to be the same as the device write count; generating, by the host, a first host message authentication code based on the host write count and a first random number; providing the storage device with a first write request, the first write request including the first host message authentication code and the first random number; receiving, at the host, a first response including a first device message authentication code from the storage device; verifying, at the host, the first response based on an increment value from the host write count, the first random number, and the first device message authentication code, wherein the verifying of the first response includes determining whether the first random number is identical to a random number included in the first response; and updating the host write count based on a result of the verifying of the first response, the updating of the host write count including incrementing the host write count to be the same as the increment value used in the verifying when the verifying of the first response succeeds.
 11. The method as claimed in claim 10, wherein the updating of the write count includes: maintaining the host write count, when the verifying of the first response fails.
 12. The method as claimed in claim 10, further comprising: generating a second random number; generating a second host message authentication code based on the updated host write count and the second random number; and providing the storage device with a second write request including the second host message authentication code and the second random number.
 13. The method as claimed in claim 12, further comprising: receiving a second response including a second device message authentication code from the storage device; and verifying the second response based on an increment value from the updated host write count, the second random number, and the second device message authentication code.
 14. The method as claimed in claim 10, wherein the verifying of the first response includes: generating a first device message verification code based on the increment value from the host write count and the first random number; and comparing the first device message verification code with the first device message authentication code.
 15. The method as claimed in claim 14, wherein the verifying of the first response further includes comparing the first random number with a third random number included in the first response.
 16. The method as claimed in claim 14, wherein: the generating of the first host message authentication code is based on a key shared with the storage device in advance, the host write count, and the first random number, and the generating of the first device message verification code is based on the key, the increment value from the host write count, and the first random number. 